charge_slab_page() and uncharge_slab_page() are not related anymore to
memcg charging and uncharging. In order to make their names less
confusing, let's rename them to account_slab_page() and
unaccount_slab_page() respectively.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Link: http://lkml.kernel.org/r/20200707173612.124425-2-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
charge_slab_page() is not using the gfp argument anymore,
remove it.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Link: http://lkml.kernel.org/r/20200707173612.124425-1-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently the kernel stack is being accounted per-zone. There is no need
to do that. In addition due to being per-zone, memcg has to keep a
separate MEMCG_KERNEL_STACK_KB. Make the stat per-node and deprecate
MEMCG_KERNEL_STACK_KB as memcg_stat_item is an extension of
node_stat_item. In addition localize the kernel stack stats updates to
account_kernel_stack().
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Link: http://lkml.kernel.org/r/20200630161539.1759185-1-shakeelb@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Instead of having two sets of kmem_caches: one for system-wide and
non-accounted allocations and the second one shared by all accounted
allocations, we can use just one.
The idea is simple: space for obj_cgroup metadata can be allocated on
demand and filled only for accounted allocations.
It allows to remove a bunch of code which is required to handle kmem_cache
clones for accounted allocations. There is no more need to create them,
accumulate statistics, propagate attributes, etc. It's a quite
significant simplification.
Also, because the total number of slab_caches is reduced almost twice (not
all kmem_caches have a memcg clone), some additional memory savings are
expected. On my devvm it additionally saves about 3.5% of slab memory.
[guro@fb.com: fix build on MIPS]
Link: http://lkml.kernel.org/r/20200717214810.3733082-1-guro@fb.com
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Link: http://lkml.kernel.org/r/20200623174037.3951353-18-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
memcg_accumulate_slabinfo() is never called with a non-root kmem_cache as
a first argument, so the is_root_cache(s) check is redundant and can be
removed without any functional change.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20200623174037.3951353-17-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently there are two lists of kmem_caches:
1) slab_caches, which contains all kmem_caches,
2) slab_root_caches, which contains only root kmem_caches.
And there is some preprocessor magic to have a single list if
CONFIG_MEMCG_KMEM isn't enabled.
It was required earlier because the number of non-root kmem_caches was
proportional to the number of memory cgroups and could reach really big
values. Now, when it cannot exceed the number of root kmem_caches, there
is really no reason to maintain two lists.
We never iterate over the slab_root_caches list on any hot paths, so it's
perfectly fine to iterate over slab_caches and filter out non-root
kmem_caches.
It allows to remove a lot of config-dependent code and two pointers from
the kmem_cache structure.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20200623174037.3951353-16-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The memcg_kmem_get_cache() function became really trivial, so let's just
inline it into the single call point: memcg_slab_pre_alloc_hook().
It will make the code less bulky and can also help the compiler to
generate a better code.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20200623174037.3951353-15-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Because the number of non-root kmem_caches doesn't depend on the number of
memory cgroups anymore and is generally not very big, there is no more
need for a dedicated workqueue.
Also, as there is no more need to pass any arguments to the
memcg_create_kmem_cache() except the root kmem_cache, it's possible to
just embed the work structure into the kmem_cache and avoid the dynamic
allocation of the work structure.
This will also simplify the synchronization: for each root kmem_cache
there is only one work. So there will be no more concurrent attempts to
create a non-root kmem_cache for a root kmem_cache: the second and all
following attempts to queue the work will fail.
On the kmem_cache destruction path there is no more need to call the
expensive flush_workqueue() and wait for all pending works to be finished.
Instead, cancel_work_sync() can be used to cancel/wait for only one work.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20200623174037.3951353-14-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is fairly big but mostly red patch, which makes all accounted slab
allocations use a single set of kmem_caches instead of creating a separate
set for each memory cgroup.
Because the number of non-root kmem_caches is now capped by the number of
root kmem_caches, there is no need to shrink or destroy them prematurely.
They can be perfectly destroyed together with their root counterparts.
This allows to dramatically simplify the management of non-root
kmem_caches and delete a ton of code.
This patch performs the following changes:
1) introduces memcg_params.memcg_cache pointer to represent the
kmem_cache which will be used for all non-root allocations
2) reuses the existing memcg kmem_cache creation mechanism
to create memcg kmem_cache on the first allocation attempt
3) memcg kmem_caches are named <kmemcache_name>-memcg,
e.g. dentry-memcg
4) simplifies memcg_kmem_get_cache() to just return memcg kmem_cache
or schedule it's creation and return the root cache
5) removes almost all non-root kmem_cache management code
(separate refcounter, reparenting, shrinking, etc)
6) makes slab debugfs to display root_mem_cgroup css id and never
show :dead and :deact flags in the memcg_slabinfo attribute.
Following patches in the series will simplify the kmem_cache creation.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20200623174037.3951353-13-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To make the memcg_kmem_bypass() function available outside of the
memcontrol.c, let's move it to memcontrol.h. The function is small and
nicely fits into static inline sort of functions.
It will be used from the slab code.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20200623174037.3951353-12-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Deprecate memory.kmem.slabinfo.
An empty file will be presented if corresponding config options are
enabled.
The interface is implementation dependent, isn't present in cgroup v2, and
is generally useful only for core mm debugging purposes. In other words,
it doesn't provide any value for the absolute majority of users.
A drgn-based replacement can be found in
tools/cgroup/memcg_slabinfo.py. It does support cgroup v1 and v2,
mimics memory.kmem.slabinfo output and also allows to get any
additional information without a need to recompile the kernel.
If a drgn-based solution is too slow for a task, a bpf-based tracing tool
can be used, which can easily keep track of all slab allocations belonging
to a memory cgroup.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20200623174037.3951353-11-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Switch to per-object accounting of non-root slab objects.
Charging is performed using obj_cgroup API in the pre_alloc hook.
Obj_cgroup is charged with the size of the object and the size of
metadata: as now it's the size of an obj_cgroup pointer. If the amount of
memory has been charged successfully, the actual allocation code is
executed. Otherwise, -ENOMEM is returned.
In the post_alloc hook if the actual allocation succeeded, corresponding
vmstats are bumped and the obj_cgroup pointer is saved. Otherwise, the
charge is canceled.
On the free path obj_cgroup pointer is obtained and used to uncharge the
size of the releasing object.
Memcg and lruvec counters are now representing only memory used by active
slab objects and do not include the free space. The free space is shared
and doesn't belong to any specific cgroup.
Global per-node slab vmstats are still modified from
(un)charge_slab_page() functions. The idea is to keep all slab pages
accounted as slab pages on system level.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20200623174037.3951353-10-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Store the obj_cgroup pointer in the corresponding place of
page->obj_cgroups for each allocated non-root slab object. Make sure that
each allocated object holds a reference to obj_cgroup.
Objcg pointer is obtained from the memcg->objcg dereferencing in
memcg_kmem_get_cache() and passed from pre_alloc_hook to post_alloc_hook.
Then in case of successful allocation(s) it's getting stored in the
page->obj_cgroups vector.
The objcg obtaining part look a bit bulky now, but it will be simplified
by next commits in the series.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20200623174037.3951353-9-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allocate and release memory to store obj_cgroup pointers for each non-root
slab page. Reuse page->mem_cgroup pointer to store a pointer to the
allocated space.
This commit temporarily increases the memory footprint of the kernel memory
accounting. To store obj_cgroup pointers we'll need a place for an
objcg_pointer for each allocated object. However, the following patches
in the series will enable sharing of slab pages between memory cgroups,
which will dramatically increase the total slab utilization. And the final
memory footprint will be significantly smaller than before.
To distinguish between obj_cgroups and memcg pointers in case when it's
not obvious which one is used (as in page_cgroup_ino()), let's always set
the lowest bit in the obj_cgroup case. The original obj_cgroups
pointer is marked to be ignored by kmemleak, which otherwise would
report a memory leak for each allocated vector.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20200623174037.3951353-8-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Obj_cgroup API provides an ability to account sub-page sized kernel
objects, which potentially outlive the original memory cgroup.
The top-level API consists of the following functions:
bool obj_cgroup_tryget(struct obj_cgroup *objcg);
void obj_cgroup_get(struct obj_cgroup *objcg);
void obj_cgroup_put(struct obj_cgroup *objcg);
int obj_cgroup_charge(struct obj_cgroup *objcg, gfp_t gfp, size_t size);
void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size);
struct mem_cgroup *obj_cgroup_memcg(struct obj_cgroup *objcg);
struct obj_cgroup *get_obj_cgroup_from_current(void);
Object cgroup is basically a pointer to a memory cgroup with a per-cpu
reference counter. It substitutes a memory cgroup in places where it's
necessary to charge a custom amount of bytes instead of pages.
All charged memory rounded down to pages is charged to the corresponding
memory cgroup using __memcg_kmem_charge().
It implements reparenting: on memcg offlining it's getting reattached to
the parent memory cgroup. Each online memory cgroup has an associated
active object cgroup to handle new allocations and the list of all
attached object cgroups. On offlining of a cgroup this list is reparented
and for each object cgroup in the list the memcg pointer is swapped to the
parent memory cgroup. It prevents long-living objects from pinning the
original memory cgroup in the memory.
The implementation is based on byte-sized per-cpu stocks. A sub-page
sized leftover is stored in an atomic field, which is a part of obj_cgroup
object. So on cgroup offlining the leftover is automatically reparented.
memcg->objcg is rcu protected. objcg->memcg is a raw pointer, which is
always pointing at a memory cgroup, but can be atomically swapped to the
parent memory cgroup. So a user must ensure the lifetime of the
cgroup, e.g. grab rcu_read_lock or css_set_lock.
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/20200623174037.3951353-7-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The reference counting of a memcg is currently coupled directly to how
many 4k pages are charged to it. This doesn't work well with Roman's new
slab controller, which maintains pools of objects and doesn't want to keep
an extra balance sheet for the pages backing those objects.
This unusual refcounting design (reference counts usually track pointers
to an object) is only for historical reasons: memcg used to not take any
css references and simply stalled offlining until all charges had been
reparented and the page counters had dropped to zero. When we got rid of
the reparenting requirement, the simple mechanical translation was to take
a reference for every charge.
More historical context can be found in commit e8ea14cc6e ("mm:
memcontrol: take a css reference for each charged page"), commit
64f2199389 ("mm: memcontrol: remove obsolete kmemcg pinning tricks") and
commit b2052564e6 ("mm: memcontrol: continue cache reclaim from offlined
groups").
The new slab controller exposes the limitations in this scheme, so let's
switch it to a more idiomatic reference counting model based on actual
kernel pointers to the memcg:
- The per-cpu stock holds a reference to the memcg its caching
- User pages hold a reference for their page->mem_cgroup. Transparent
huge pages will no longer acquire tail references in advance, we'll
get them if needed during the split.
- Kernel pages hold a reference for their page->mem_cgroup
- Pages allocated in the root cgroup will acquire and release css
references for simplicity. css_get() and css_put() optimize that.
- The current memcg_charge_slab() already hacked around the per-charge
references; this change gets rid of that as well.
- tcp accounting will handle reference in mem_cgroup_sk_{alloc,free}
Roman:
1) Rebased on top of the current mm tree: added css_get() in
mem_cgroup_charge(), dropped mem_cgroup_try_charge() part
2) I've reformatted commit references in the commit log to make
checkpatch.pl happy.
[hughd@google.com: remove css_put_many() from __mem_cgroup_clear_mc()]
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2007302011450.2347@eggly.anvils
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/20200623174037.3951353-6-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit implements SLUB version of the obj_to_index() function, which
will be required to calculate the offset of obj_cgroup in the obj_cgroups
vector to store/obtain the objcg ownership data.
To make it faster, let's repeat the SLAB's trick introduced by commit
6a2d7a955d ("SLAB: use a multiply instead of a divide in
obj_to_index()") and avoid an expensive division.
Vlastimil Babka noticed, that SLUB does have already a similar function
called slab_index(), which is defined only if SLUB_DEBUG is enabled. The
function does a similar math, but with a division, and it also takes a
page address instead of a page pointer.
Let's remove slab_index() and replace it with the new helper
__obj_to_index(), which takes a page address. obj_to_index() will be a
simple wrapper taking a page pointer and passing page_address(page) into
__obj_to_index().
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20200623174037.3951353-5-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In order to prepare for per-object slab memory accounting, convert
NR_SLAB_RECLAIMABLE and NR_SLAB_UNRECLAIMABLE vmstat items to bytes.
To make it obvious, rename them to NR_SLAB_RECLAIMABLE_B and
NR_SLAB_UNRECLAIMABLE_B (similar to NR_KERNEL_STACK_KB).
Internally global and per-node counters are stored in pages, however memcg
and lruvec counters are stored in bytes. This scheme may look weird, but
only for now. As soon as slab pages will be shared between multiple
cgroups, global and node counters will reflect the total number of slab
pages. However memcg and lruvec counters will be used for per-memcg slab
memory tracking, which will take separate kernel objects in the account.
Keeping global and node counters in pages helps to avoid additional
overhead.
The size of slab memory shouldn't exceed 4Gb on 32-bit machines, so it
will fit into atomic_long_t we use for vmstats.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20200623174037.3951353-4-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To implement per-object slab memory accounting, we need to convert slab
vmstat counters to bytes. Actually, out of 4 levels of counters: global,
per-node, per-memcg and per-lruvec only two last levels will require
byte-sized counters. It's because global and per-node counters will be
counting the number of slab pages, and per-memcg and per-lruvec will be
counting the amount of memory taken by charged slab objects.
Converting all vmstat counters to bytes or even all slab counters to bytes
would introduce an additional overhead. So instead let's store global and
per-node counters in pages, and memcg and lruvec counters in bytes.
To make the API clean all access helpers (both on the read and write
sides) are dealing with bytes.
To avoid back-and-forth conversions a new flavor of read-side helpers is
introduced, which always returns values in pages: node_page_state_pages()
and global_node_page_state_pages().
Actually new helpers are just reading raw values. Old helpers are simple
wrappers, which will complain on an attempt to read byte value, because at
the moment no one actually needs bytes.
Thanks to Johannes Weiner for the idea of having the byte-sized API on top
of the page-sized internal storage.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20200623174037.3951353-3-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "The new cgroup slab memory controller", v7.
The patchset moves the accounting from the page level to the object level.
It allows to share slab pages between memory cgroups. This leads to a
significant win in the slab utilization (up to 45%) and the corresponding
drop in the total kernel memory footprint. The reduced number of
unmovable slab pages should also have a positive effect on the memory
fragmentation.
The patchset makes the slab accounting code simpler: there is no more need
in the complicated dynamic creation and destruction of per-cgroup slab
caches, all memory cgroups use a global set of shared slab caches. The
lifetime of slab caches is not more connected to the lifetime of memory
cgroups.
The more precise accounting does require more CPU, however in practice the
difference seems to be negligible. We've been using the new slab
controller in Facebook production for several months with different
workloads and haven't seen any noticeable regressions. What we've seen
were memory savings in order of 1 GB per host (it varied heavily depending
on the actual workload, size of RAM, number of CPUs, memory pressure,
etc).
The third version of the patchset added yet another step towards the
simplification of the code: sharing of slab caches between accounted and
non-accounted allocations. It comes with significant upsides (most
noticeable, a complete elimination of dynamic slab caches creation) but
not without some regression risks, so this change sits on top of the
patchset and is not completely merged in. So in the unlikely event of a
noticeable performance regression it can be reverted separately.
The slab memory accounting works in exactly the same way for SLAB and
SLUB. With both allocators the new controller shows significant memory
savings, with SLUB the difference is bigger. On my 16-core desktop
machine running Fedora 32 the size of the slab memory measured after the
start of the system was lower by 58% and 38% with SLUB and SLAB
correspondingly.
As an estimation of a potential CPU overhead, below are results of
slab_bulk_test01 test, kindly provided by Jesper D. Brouer. He also
helped with the evaluation of results.
The test can be found here: https://github.com/netoptimizer/prototype-kernel/
The smallest number in each row should be picked for a comparison.
SLUB-patched - bulk-API
- SLUB-patched : bulk_quick_reuse objects=1 : 187 - 90 - 224 cycles(tsc)
- SLUB-patched : bulk_quick_reuse objects=2 : 110 - 53 - 133 cycles(tsc)
- SLUB-patched : bulk_quick_reuse objects=3 : 88 - 95 - 42 cycles(tsc)
- SLUB-patched : bulk_quick_reuse objects=4 : 91 - 85 - 36 cycles(tsc)
- SLUB-patched : bulk_quick_reuse objects=8 : 32 - 66 - 32 cycles(tsc)
SLUB-original - bulk-API
- SLUB-original: bulk_quick_reuse objects=1 : 87 - 87 - 142 cycles(tsc)
- SLUB-original: bulk_quick_reuse objects=2 : 52 - 53 - 53 cycles(tsc)
- SLUB-original: bulk_quick_reuse objects=3 : 42 - 42 - 91 cycles(tsc)
- SLUB-original: bulk_quick_reuse objects=4 : 91 - 37 - 37 cycles(tsc)
- SLUB-original: bulk_quick_reuse objects=8 : 31 - 79 - 76 cycles(tsc)
SLAB-patched - bulk-API
- SLAB-patched : bulk_quick_reuse objects=1 : 67 - 67 - 140 cycles(tsc)
- SLAB-patched : bulk_quick_reuse objects=2 : 55 - 46 - 46 cycles(tsc)
- SLAB-patched : bulk_quick_reuse objects=3 : 93 - 94 - 39 cycles(tsc)
- SLAB-patched : bulk_quick_reuse objects=4 : 35 - 88 - 85 cycles(tsc)
- SLAB-patched : bulk_quick_reuse objects=8 : 30 - 30 - 30 cycles(tsc)
SLAB-original- bulk-API
- SLAB-original: bulk_quick_reuse objects=1 : 143 - 136 - 67 cycles(tsc)
- SLAB-original: bulk_quick_reuse objects=2 : 45 - 46 - 46 cycles(tsc)
- SLAB-original: bulk_quick_reuse objects=3 : 38 - 39 - 39 cycles(tsc)
- SLAB-original: bulk_quick_reuse objects=4 : 35 - 87 - 87 cycles(tsc)
- SLAB-original: bulk_quick_reuse objects=8 : 29 - 66 - 30 cycles(tsc)
This patch (of 19):
To convert memcg and lruvec slab counters to bytes there must be a way to
change these counters without touching node counters. Factor out
__mod_memcg_lruvec_state() out of __mod_lruvec_state().
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20200623174037.3951353-1-guro@fb.com
Link: http://lkml.kernel.org/r/20200623174037.3951353-2-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Historically the kernel memory accounting was an opt-in feature, which
could be enabled for individual cgroups. But now it's not true, and it's
on by default both on cgroup v1 and cgroup v2. And as long as a user has
at least one non-root memory cgroup, the kernel memory accounting is on.
So in most setups it's either always on (if memory cgroups are in use and
kmem accounting is not disabled), either always off (otherwise).
memcg_kmem_enabled() is used in many places to guard the kernel memory
accounting code. If memcg_kmem_enabled() can reverse from returning true
to returning false (as now), we can't rely on it on release paths and have
to check if it was on before.
If we'll make memcg_kmem_enabled() irreversible (always returning true
after returning it for the first time), it'll make the general logic more
simple and robust. It also will allow to guard some checks which
otherwise would stay unguarded.
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Link: http://lkml.kernel.org/r/20200702180926.1330769-1-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The default is still set to inode32 for backwards compatibility, but
system administrators can opt in to the new 64-bit inode numbers by
either:
1. Passing inode64 on the command line when mounting, or
2. Configuring the kernel with CONFIG_TMPFS_INODE64=y
The inode64 and inode32 names are used based on existing precedent from
XFS.
[hughd@google.com: Kconfig fixes]
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2008011928010.13320@eggly.anvils
Signed-off-by: Chris Down <chris@chrisdown.name>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/8b23758d0c66b5e2263e08baf9c4b6a7565cbd8f.1594661218.git.chris@chrisdown.name
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "tmpfs: inode: Reduce risk of inum overflow", v7.
In Facebook production we are seeing heavy i_ino wraparounds on tmpfs. On
affected tiers, in excess of 10% of hosts show multiple files with
different content and the same inode number, with some servers even having
as many as 150 duplicated inode numbers with differing file content.
This causes actual, tangible problems in production. For example, we have
complaints from those working on remote caches that their application is
reporting cache corruptions because it uses (device, inodenum) to
establish the identity of a particular cache object, but because it's not
unique any more, the application refuses to continue and reports cache
corruption. Even worse, sometimes applications may not even detect the
corruption but may continue anyway, causing phantom and hard to debug
behaviour.
In general, userspace applications expect that (device, inodenum) should
be enough to be uniquely point to one inode, which seems fair enough. One
might also need to check the generation, but in this case:
1. That's not currently exposed to userspace
(ioctl(...FS_IOC_GETVERSION...) returns ENOTTY on tmpfs);
2. Even with generation, there shouldn't be two live inodes with the
same inode number on one device.
In order to mitigate this, we take a two-pronged approach:
1. Moving inum generation from being global to per-sb for tmpfs. This
itself allows some reduction in i_ino churn. This works on both 64-
and 32- bit machines.
2. Adding inode{64,32} for tmpfs. This fix is supported on machines with
64-bit ino_t only: we allow users to mount tmpfs with a new inode64
option that uses the full width of ino_t, or CONFIG_TMPFS_INODE64.
You can see how this compares to previous related patches which didn't
implement this per-superblock:
- https://patchwork.kernel.org/patch/11254001/
- https://patchwork.kernel.org/patch/11023915/
This patch (of 2):
get_next_ino has a number of problems:
- It uses and returns a uint, which is susceptible to become overflowed
if a lot of volatile inodes that use get_next_ino are created.
- It's global, with no specificity per-sb or even per-filesystem. This
means it's not that difficult to cause inode number wraparounds on a
single device, which can result in having multiple distinct inodes
with the same inode number.
This patch adds a per-superblock counter that mitigates the second case.
This design also allows us to later have a specific i_ino size per-device,
for example, allowing users to choose whether to use 32- or 64-bit inodes
for each tmpfs mount. This is implemented in the next commit.
For internal shmem mounts which may be less tolerant to spinlock delays,
we implement a percpu batching scheme which only takes the stat_lock at
each batch boundary.
Signed-off-by: Chris Down <chris@chrisdown.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/cover.1594661218.git.chris@chrisdown.name
Link: http://lkml.kernel.org/r/1986b9d63b986f08ec07a4aa4b2275e718e47d8a.1594661218.git.chris@chrisdown.name
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
swap_readpage() does the sync io for one page, the io is not big,
normally, the io can be finished quickly, but it may take long time or
wait forever in case of io failure or discard.
This patch uses blk_io_schedule() instead of io_schedule() to avoid task
hung and crash (when set /proc/sys/kernel/hung_task_panic) when the above
exception occurs.
This is similar to the hung task avoidance in submit_bio_wait(),
blk_execute_rq() and __blkdev_direct_IO().
Signed-off-by: Xianting Tian <xianting_tian@126.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Hugh Dickins <hughd@google.com>
Link: http://lkml.kernel.org/r/1596461807-21087-1-git-send-email-xianting_tian@126.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix W=1 compile warnings (invalid kerneldoc):
mm/swap_state.c:742: warning: Function parameter or member 'fentry' not described in 'swap_vma_readahead'
mm/swap_state.c:742: warning: Excess function parameter 'entry' description in 'swap_vma_readahead'
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200728171109.28687-2-krzk@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Because enable_swap_slots_cache can only become true in
enable_swap_slots_cache(), and depends on swap_slot_cache_initialized is
true before. That means, when enable_swap_slots_cache is true,
swap_slot_cache_initialized is true also.
So the condition:
"swap_slot_cache_enabled && swap_slot_cache_initialized"
can be reduced to "swap_slot_cache_enabled"
And in mathematics:
"!swap_slot_cache_enabled || !swap_slot_cache_initialized"
is equal to "!(swap_slot_cache_enabled && swap_slot_cache_initialized)"
So no functional change.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Link: http://lkml.kernel.org/r/20200430061143.450-4-thunder.leizhen@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Whether swap_slot_cache_initialized is true or false,
__reenable_swap_slots_cache() is always called. To make this meaning
clear, leave only one call to __reenable_swap_slots_cache(). This also
make it clearer what extra needs be done when swap_slot_cache_initialized
is false.
No functional change.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Link: http://lkml.kernel.org/r/20200430061143.450-3-thunder.leizhen@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "clean up some functions in mm/swap_slots.c".
When I studied the code of mm/swap_slots.c, I found some places can be
improved.
This patch (of 3):
Both "slots" and "slots_ret" are only need to be freed when cache already
allocated. Make them closer, seems more clear.
No functional change.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Link: http://lkml.kernel.org/r/20200430061143.450-1-thunder.leizhen@huawei.com
Link: http://lkml.kernel.org/r/20200430061143.450-2-thunder.leizhen@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The return value of populate_vma_page_range() is consistent with
__get_user_pages(), and so is the function comment of return value.
Signed-off-by: Tang Yizhou <tangyizhou@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: http://lkml.kernel.org/r/20200720034303.29920-1-tangyizhou@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
FGP_{WRITE|NOFS|NOWAIT} were missed in pagecache_get_page's kerneldoc
comment.
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Gang Deng <gavin.dg@linux.alibaba.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/1593031747-4249-1-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit bbddabe2e4 ("mm: filemap: only do access activations on
reads"), mark_page_accessed() is called for reads only. But the idle flag
is cleared by mark_page_accessed() so the idle flag won't get cleared if
the page is write accessed only.
Basically idle page tracking is used to estimate workingset size of
workload, noticeable size of workingset might be missed if the idle flag
is not maintained correctly.
It seems good enough to just clear idle flag for write operations.
Fixes: bbddabe2e4 ("mm: filemap: only do access activations on reads")
Reported-by: Gang Deng <gavin.dg@linux.alibaba.com>
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/1593020612-13051-1-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If a compound page is being split while dump_page() is being run on that
page, we can end up calling compound_mapcount() on a page that is no
longer compound. This leads to a crash (already seen at least once in the
field), due to the VM_BUG_ON_PAGE() assertion inside compound_mapcount().
(The above is from Matthew Wilcox's analysis of Qian Cai's bug report.)
A similar problem is possible, via compound_pincount() instead of
compound_mapcount().
In order to avoid this kind of crash, make dump_page() slightly more
robust, by providing a pair of simpler routines that don't contain
assertions: head_mapcount() and head_pincount().
For debug tools, we don't want to go *too* far in this direction, but this
is a simple small fix, and the crash has already been seen, so it's a good
trade-off.
Reported-by: Qian Cai <cai@lca.pw>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Link: http://lkml.kernel.org/r/20200804214807.169256-1-jhubbard@nvidia.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The actual address of the struct page isn't particularly helpful, while
the hashed address helps match with other messages elsewhere. Add the PFN
that the page refers to in order to help diagnose problems where the page
is improperly aligned for the purpose.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: William Kucharski <william.kucharski@oracle.com>
Link: http://lkml.kernel.org/r/20200709202117.7216-7-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The inode number helps correlate this page with debug messages elsewhere
in the kernel.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: William Kucharski <william.kucharski@oracle.com>
Link: http://lkml.kernel.org/r/20200709202117.7216-6-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is simpler to use than copy_from_kernel_nofault(). Also make some of
the related error messages less verbose.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: William Kucharski <william.kucharski@oracle.com>
Link: http://lkml.kernel.org/r/20200709202117.7216-5-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tail page flags contain very little useful information. Print the head
page's flags instead. While the flags will contain "head" for tail pages,
this should not be too confusing as the previous line starts with the word
"head:" and so the flags should be interpreted as belonging to the head
page.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: William Kucharski <william.kucharski@oracle.com>
Link: http://lkml.kernel.org/r/20200709202117.7216-4-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Simplify both the implementation and the output by splitting all the
compound page information onto a second line.
Reported-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: William Kucharski <william.kucharski@oracle.com>
Link: http://lkml.kernel.org/r/20200709202117.7216-3-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds a specific description file for all arch page table helpers which
is in sync with the semantics being tested via CONFIG_DEBUG_VM_PGTABLE. All
future changes either to these descriptions here or the debug test should
always remain in sync.
[anshuman.khandual@arm.com: fold in Mike's patch for the rst document, fix typos in the rst document]
Link: http://lkml.kernel.org/r/1594610587-4172-5-git-send-email-anshuman.khandual@arm.com
Suggested-by: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Zi Yan <ziy@nvidia.com>
Link: http://lkml.kernel.org/r/1593996516-7186-5-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm/debug_vm_pgtable: Add some more tests", v5.
This series adds some more arch page table helper validation tests which
are related to core and advanced memory functions. This also creates a
documentation, enlisting expected semantics for all page table helpers as
suggested by Mike Rapoport previously
(https://lkml.org/lkml/2020/1/30/40).
There are many TRANSPARENT_HUGEPAGE and ARCH_HAS_TRANSPARENT_HUGEPAGE_PUD
ifdefs scattered across the test. But consolidating all the fallback
stubs is not very straight forward because
ARCH_HAS_TRANSPARENT_HUGEPAGE_PUD is not explicitly dependent on
ARCH_HAS_TRANSPARENT_HUGEPAGE.
Tested on arm64, x86 platforms but only build tested on all other enabled
platforms through ARCH_HAS_DEBUG_VM_PGTABLE i.e powerpc, arc, s390. The
following failure on arm64 still exists which was mentioned previously.
It will be fixed with the upcoming THP migration on arm64 enablement
series.
WARNING .... mm/debug_vm_pgtable.c:860 debug_vm_pgtable+0x940/0xa54
WARN_ON(!pmd_present(pmd_mkinvalid(pmd_mkhuge(pmd))))
This patch (of 4):
This adds new tests validating arch page table helpers for these following
core memory features. These tests create and test specific mapping types
at various page table levels.
1. SPECIAL mapping
2. PROTNONE mapping
3. DEVMAP mapping
4. SOFTDIRTY mapping
5. SWAP mapping
6. MIGRATION mapping
7. HUGETLB mapping
8. THP mapping
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Vineet Gupta <vgupta@synopsys.com> [arc]
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Link: http://lkml.kernel.org/r/1594610587-4172-1-git-send-email-anshuman.khandual@arm.com
Link: http://lkml.kernel.org/r/1593996516-7186-1-git-send-email-anshuman.khandual@arm.com
Link: http://lkml.kernel.org/r/1593996516-7186-2-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide the necessary KCSAN checks to assist with debugging racy
use-after-frees. While KASAN is more reliable at generally catching such
use-after-frees (due to its use of a quarantine), it can be difficult to
debug racy use-after-frees. If a reliable reproducer exists, KCSAN can
assist in debugging such issues.
Note: ASSERT_EXCLUSIVE_ACCESS is a convenience wrapper if the size is
simply sizeof(var). Instead, here we just use __kcsan_check_access()
explicitly to pass the correct size.
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Link: http://lkml.kernel.org/r/20200623072653.114563-1-elver@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is no point in using lockdep_assert_held() unlock that is about to
be unlocked. It works only with lockdep and lockdep will complain if
spin_unlock() is used on a lock that has not been locked.
Remove superfluous lockdep_assert_held().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Christopher Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200618201234.795692-2-bigeasy@linutronix.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
cache_from_obj() was added by commit b9ce5ef49f ("sl[au]b: always get
the cache from its page in kmem_cache_free()") to support kmemcg, where
per-memcg cache can be different from the root one, so we can't use the
kmem_cache pointer given to kmem_cache_free().
Prior to that commit, SLUB already had debugging check+warning that could
be enabled to compare the given kmem_cache pointer to one referenced by
the slab page where the object-to-be-freed resides. This check was moved
to cache_from_obj(). Later the check was also enabled for
SLAB_FREELIST_HARDENED configs by commit 598a0717a8 ("mm/slab: validate
cache membership under freelist hardening").
These checks and warnings can be useful especially for the debugging,
which can be improved. Commit 598a0717a8 changed the pr_err() with
WARN_ON_ONCE() to WARN_ONCE() so only the first hit is now reported,
others are silent. This patch changes it to WARN() so that all errors are
reported.
It's also useful to print SLUB allocation/free tracking info for the
offending object, if tracking is enabled. Thus, export the SLUB
print_tracking() function and provide an empty one for SLAB.
For SLUB we can also benefit from the static key check in
kmem_cache_debug_flags(), but we need to move this function to slab.h and
declare the static key there.
[1] https://lore.kernel.org/r/20200608230654.828134-18-guro@fb.com
[vbabka@suse.cz: avoid bogus WARN()]
Link: https://lore.kernel.org/r/20200623090213.GW5535@shao2-debian
Link: http://lkml.kernel.org/r/b33e0fa7-cd28-4788-9e54-5927846329ef@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Garrett <mjg59@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Vijayanand Jitta <vjitta@codeaurora.org>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Link: http://lkml.kernel.org/r/afeda7ac-748b-33d8-a905-56b708148ad5@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The function cache_from_obj() was added by commit b9ce5ef49f ("sl[au]b:
always get the cache from its page in kmem_cache_free()") to support
kmemcg, where per-memcg cache can be different from the root one, so we
can't use the kmem_cache pointer given to kmem_cache_free().
Prior to that commit, SLUB already had debugging check+warning that could
be enabled to compare the given kmem_cache pointer to one referenced by
the slab page where the object-to-be-freed resides. This check was moved
to cache_from_obj(). Later the check was also enabled for
SLAB_FREELIST_HARDENED configs by commit 598a0717a8 ("mm/slab: validate
cache membership under freelist hardening").
These checks and warnings can be useful especially for the debugging,
which can be improved. Commit 598a0717a8 changed the pr_err() with
WARN_ON_ONCE() to WARN_ONCE() so only the first hit is now reported,
others are silent. This patch changes it to WARN() so that all errors are
reported.
It's also useful to print SLUB allocation/free tracking info for the
offending object, if tracking is enabled. We could export the SLUB
print_tracking() function and provide an empty one for SLAB, or realize
that both the debugging and hardening cases in cache_from_obj() are only
supported by SLUB anyway. So this patch moves cache_from_obj() from
slab.h to separate instances in slab.c and slub.c, where the SLAB version
only does the kmemcg lookup and even could be completely removed once the
kmemcg rework [1] is merged. The SLUB version can thus easily use the
print_tracking() function. It can also use the kmem_cache_debug_flags()
static key check for improved performance in kernels without the hardening
and with debugging not enabled on boot.
[1] https://lore.kernel.org/r/20200608230654.828134-18-guro@fb.com
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Vijayanand Jitta <vjitta@codeaurora.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Link: http://lkml.kernel.org/r/20200610163135.17364-10-vbabka@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are few more places in SLUB that could benefit from reduced overhead
of the static key introduced by a previous patch:
- setup_object_debug() called on each object in newly allocated slab page
- setup_page_debug() called on newly allocated slab page
- __free_slab() called on freed slab page
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Vijayanand Jitta <vjitta@codeaurora.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Link: http://lkml.kernel.org/r/20200610163135.17364-9-vbabka@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are few places that call kmem_cache_debug(s) (which tests if any of
debug flags are enabled for a cache) immediately followed by a test for a
specific flag. The compiler can probably eliminate the extra check, but
we can make the code nicer by introducing kmem_cache_debug_flags() that
works like kmem_cache_debug() (including the static key check) but tests
for specific flag(s). The next patches will add more users.
[vbabka@suse.cz: change return from int to bool, per Kees. Add VM_WARN_ON_ONCE() for invalid flags, per Roman]
Link: http://lkml.kernel.org/r/949b90ed-e0f0-07d7-4d21-e30ec0958a7c@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Jann Horn <jannh@google.com>
Cc: Vijayanand Jitta <vjitta@codeaurora.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Link: http://lkml.kernel.org/r/20200610163135.17364-8-vbabka@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
One advantage of CONFIG_SLUB_DEBUG is that a generic distro kernel can be
built with the option enabled, but it's inactive until simply enabled on
boot, without rebuilding the kernel. With a static key, we can further
eliminate the overhead of checking whether a cache has a particular debug
flag enabled if we know that there are no such caches (slub_debug was not
enabled during boot). We use the same mechanism also for e.g.
page_owner, debug_pagealloc or kmemcg functionality.
This patch introduces the static key and makes the general check for
per-cache debug flags kmem_cache_debug() use it. This benefits several
call sites, including (slow path but still rather frequent) __slab_free().
The next patches will add more uses.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Jann Horn <jannh@google.com>
Cc: Vijayanand Jitta <vjitta@codeaurora.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Link: http://lkml.kernel.org/r/20200610163135.17364-7-vbabka@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The attribute reflects the SLAB_RECLAIM_ACCOUNT cache flag. It's not
clear why this attribute was writable in the first place, as it's tied to
how the cache is used by its creator, it's not a user tunable.
Furthermore:
- it affects slab merging, but that's not being checked while toggled
- if affects whether __GFP_RECLAIMABLE flag is used to allocate page, but
the runtime toggle doesn't update allocflags
- it affects cache_vmstat_idx() so runtime toggling might lead to incosistency
of NR_SLAB_RECLAIMABLE and NR_SLAB_UNRECLAIMABLE
Thus make it read-only.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Jann Horn <jannh@google.com>
Cc: Vijayanand Jitta <vjitta@codeaurora.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Link: http://lkml.kernel.org/r/20200610163135.17364-6-vbabka@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
SLUB_DEBUG creates several files under /sys/kernel/slab/<cache>/ that can
be read to check if the respective debugging options are enabled for given
cache. Some options, namely sanity_checks, trace, and failslab can be
also enabled and disabled at runtime by writing into the files.
The runtime toggling is racy. Some options disable __CMPXCHG_DOUBLE when
enabled, which means that in case of concurrent allocations, some can
still use __CMPXCHG_DOUBLE and some not, leading to potential corruption.
The s->flags field is also not updated or checked atomically. The
simplest solution is to remove the runtime toggling. The extended
slub_debug boot parameter syntax introduced by earlier patch should allow
to fine-tune the debugging configuration during boot with same
granularity.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Jann Horn <jannh@google.com>
Cc: Vijayanand Jitta <vjitta@codeaurora.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Link: http://lkml.kernel.org/r/20200610163135.17364-5-vbabka@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
SLUB allows runtime changing of page allocation order by writing into the
/sys/kernel/slab/<cache>/order file. Jann has reported [1] that this
interface allows the order to be set too small, leading to crashes.
While it's possible to fix the immediate issue, closer inspection reveals
potential races. Storing the new order calls calculate_sizes() which
non-atomically updates a lot of kmem_cache fields while the cache is still
in use. Unexpected behavior might occur even if the fields are set to the
same value as they were.
This could be fixed by splitting out the part of calculate_sizes() that
depends on forced_order, so that we only update kmem_cache.oo field. This
could still race with init_cache_random_seq(), shuffle_freelist(),
allocate_slab(). Perhaps it's possible to audit and e.g. add some
READ_ONCE/WRITE_ONCE accesses, it might be easier just to remove the
runtime order changes, which is what this patch does. If there are valid
usecases for per-cache order setting, we could e.g. extend the boot
parameters to do that.
[1] https://lore.kernel.org/r/CAG48ez31PP--h6_FzVyfJ4H86QYczAFPdxtJHUEEan+7VJETAQ@mail.gmail.com
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Vijayanand Jitta <vjitta@codeaurora.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Link: http://lkml.kernel.org/r/20200610163135.17364-4-vbabka@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
SLUB_DEBUG creates several files under /sys/kernel/slab/<cache>/ that can
be read to check if the respective debugging options are enabled for given
cache. The options can be also toggled at runtime by writing into the
files. Some of those, namely red_zone, poison, and store_user can be
toggled only when no objects yet exist in the cache.
Vijayanand reports [1] that there is a problem with freelist randomization
if changing the debugging option's state results in different number of
objects per page, and the random sequence cache needs thus needs to be
recomputed.
However, another problem is that the check for "no objects yet exist in
the cache" is racy, as noted by Jann [2] and fixing that would add
overhead or otherwise complicate the allocation/freeing paths. Thus it
would be much simpler just to remove the runtime toggling support. The
documentation describes it's "In case you forgot to enable debugging on
the kernel command line", but the neccessity of having no objects limits
its usefulness anyway for many caches.
Vijayanand describes an use case [3] where debugging is enabled for all
but zram caches for memory overhead reasons, and using the runtime toggles
was the only way to achieve such configuration. After the previous patch
it's now possible to do that directly from the kernel boot option, so we
can remove the dangerous runtime toggles by making the /sys attribute
files read-only.
While updating it, also improve the documentation of the debugging /sys files.
[1] https://lkml.kernel.org/r/1580379523-32272-1-git-send-email-vjitta@codeaurora.org
[2] https://lore.kernel.org/r/CAG48ez31PP--h6_FzVyfJ4H86QYczAFPdxtJHUEEan+7VJETAQ@mail.gmail.com
[3] https://lore.kernel.org/r/1383cd32-1ddc-4dac-b5f8-9c42282fa81c@codeaurora.org
Reported-by: Vijayanand Jitta <vjitta@codeaurora.org>
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Link: http://lkml.kernel.org/r/20200610163135.17364-3-vbabka@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "slub_debug fixes and improvements".
The slub_debug kernel boot parameter can either apply a single set of
options to all caches or a list of caches. There is a use case where
debugging is applied for all caches and then disabled at runtime for
specific caches, for performance and memory consumption reasons [1]. As
runtime changes are dangerous, extend the boot parameter syntax so that
multiple blocks of either global or slab-specific options can be
specified, with blocks delimited by ';'. This will also support the use
case of [1] without runtime changes.
For details see the updated Documentation/vm/slub.rst
[1] https://lore.kernel.org/r/1383cd32-1ddc-4dac-b5f8-9c42282fa81c@codeaurora.org
[weiyongjun1@huawei.com: make parse_slub_debug_flags() static]
Link: http://lkml.kernel.org/r/20200702150522.4940-1-weiyongjun1@huawei.com
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Jann Horn <jannh@google.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Vijayanand Jitta <vjitta@codeaurora.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Link: http://lkml.kernel.org/r/20200610163135.17364-2-vbabka@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kmem_list3 has been renamed to kmem_cache_node long long ago so update it.
References:
6744f087ba ("slab: Common name for the per node structures")
ce8eb6c424 ("slab: Rename list3/l3 to node")
Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Link: http://lkml.kernel.org/r/20200722033355.26908-1-yangx.jy@cn.fujitsu.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kmalloc cannot allocate memory from HIGHMEM. Allocating large amounts of
memory currently bypasses the check and will simply leak the memory when
page_address() returns NULL. To fix this, factor the GFP_SLAB_BUG_MASK
check out of slab & slub, and call it from kmalloc_order() as well. In
order to make the code clear, the warning message is put in one place.
Signed-off-by: Long Li <lonuxli.64@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Link: http://lkml.kernel.org/r/20200704035027.GA62481@lilong
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Similar to commit ce6fa91b93 ("mm/slub.c: add a naive detection of
double free or corruption"), add a very cheap double-free check for SLAB
under CONFIG_SLAB_FREELIST_HARDENED. With this added, the
"SLAB_FREE_DOUBLE" LKDTM test passes under SLAB:
lkdtm: Performing direct entry SLAB_FREE_DOUBLE
lkdtm: Attempting double slab free ...
------------[ cut here ]------------
WARNING: CPU: 2 PID: 2193 at mm/slab.c:757 ___cache _free+0x325/0x390
[keescook@chromium.org: fix misplaced __free_one()]
Link: http://lkml.kernel.org/r/202006261306.0D82A2B@keescook
Link: https://lore.kernel.org/lkml/7ff248c7-d447-340c-a8e2-8c02972aca70@infradead.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Randy Dunlap <rdunlap@infradead.org> [build tested]
Cc: Roman Gushchin <guro@fb.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Cc: Matthew Garrett <mjg59@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Vijayanand Jitta <vjitta@codeaurora.org>
Link: http://lkml.kernel.org/r/20200625215548.389774-3-keescook@chromium.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Other mm routines such as kfree() and kzfree() silently do the right thing
if passed a NULL pointer, so ksize() should do the same.
Signed-off-by: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Link: http://lkml.kernel.org/r/20200616225409.4670-1-william.kucharski@oracle.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As said by Linus:
A symmetric naming is only helpful if it implies symmetries in use.
Otherwise it's actively misleading.
In "kzalloc()", the z is meaningful and an important part of what the
caller wants.
In "kzfree()", the z is actively detrimental, because maybe in the
future we really _might_ want to use that "memfill(0xdeadbeef)" or
something. The "zero" part of the interface isn't even _relevant_.
The main reason that kzfree() exists is to clear sensitive information
that should not be leaked to other future users of the same memory
objects.
Rename kzfree() to kfree_sensitive() to follow the example of the recently
added kvfree_sensitive() and make the intention of the API more explicit.
In addition, memzero_explicit() is used to clear the memory to make sure
that it won't get optimized away by the compiler.
The renaming is done by using the command sequence:
git grep -w --name-only kzfree |\
xargs sed -i 's/kzfree/kfree_sensitive/'
followed by some editing of the kfree_sensitive() kerneldoc and adding
a kzfree backward compatibility macro in slab.h.
[akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h]
[akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more]
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Jason A . Donenfeld" <Jason@zx2c4.com>
Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Especially with memory hotplug, we can have offline sections (with a
garbage memmap) and overlapping zones. We have to make sure to only touch
initialized memmaps (online sections managed by the buddy) and that the
zone matches, to not move pages between zones.
To test if this can actually happen, I added a simple
BUG_ON(page_zone(page_i) != page_zone(page_j));
right before the swap. When hotplugging a 256M DIMM to a 4G x86-64 VM and
onlining the first memory block "online_movable" and the second memory
block "online_kernel", it will trigger the BUG, as both zones (NORMAL and
MOVABLE) overlap.
This might result in all kinds of weird situations (e.g., double
allocations, list corruptions, unmovable allocations ending up in the
movable zone).
Fixes: e900a918b0 ("mm: shuffle initial free memory to improve memory-side-cache utilization")
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org> [5.2+]
Link: http://lkml.kernel.org/r/20200624094741.9918-2-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On x86_64, when CONFIG_MMU_NOTIFIER is not set/enabled, there is a
compiler error:
mm/migrate.c: In function 'migrate_vma_collect':
mm/migrate.c:2481:7: error: 'struct mmu_notifier_range' has no member named 'migrate_pgmap_owner'
range.migrate_pgmap_owner = migrate->pgmap_owner;
^
Fixes: 998427b3ad ("mm/notifier: add migration invalidation type")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "Jason Gunthorpe" <jgg@mellanox.com>
Link: http://lkml.kernel.org/r/20200806193353.7124-1-rcampbell@nvidia.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Add support for (optionally) using queued spinlocks & rwlocks.
- Support for a new faster system call ABI using the scv instruction on Power9
or later.
- Drop support for the PROT_SAO mmap/mprotect flag as it will be unsupported on
Power10 and future processors, leaving us with no way to implement the
functionality it requests. This risks breaking userspace, though we believe
it is unused in practice.
- A bug fix for, and then the removal of, our custom stack expansion checking.
We now allow stack expansion up to the rlimit, like other architectures.
- Remove the remnants of our (previously disabled) topology update code, which
tried to react to NUMA layout changes on virtualised systems, but was prone
to crashes and other problems.
- Add PMU support for Power10 CPUs.
- A change to our signal trampoline so that we don't unbalance the link stack
(branch return predictor) in the signal delivery path.
- Lots of other cleanups, refactorings, smaller features and so on as usual.
Thanks to:
Abhishek Goel, Alastair D'Silva, Alexander A. Klimov, Alexey Kardashevskiy,
Alistair Popple, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Anton
Blanchard, Arnd Bergmann, Athira Rajeev, Balamuruhan S, Bharata B Rao, Bill
Wendling, Bin Meng, Cédric Le Goater, Chris Packham, Christophe Leroy,
Christoph Hellwig, Daniel Axtens, Dan Williams, David Lamparter, Desnes A.
Nunes do Rosario, Erhard F., Finn Thain, Frederic Barrat, Ganesh Goudar,
Gautham R. Shenoy, Geoff Levand, Greg Kurz, Gustavo A. R. Silva, Hari Bathini,
Harish, Imre Kaloz, Joel Stanley, Joe Perches, John Crispin, Jordan Niethe,
Kajol Jain, Kamalesh Babulal, Kees Cook, Laurent Dufour, Leonardo Bras, Li
RongQing, Madhavan Srinivasan, Mahesh Salgaonkar, Mark Cave-Ayland, Michal
Suchanek, Milton Miller, Mimi Zohar, Murilo Opsfelder Araujo, Nathan
Chancellor, Nathan Lynch, Naveen N. Rao, Nayna Jain, Nicholas Piggin, Oliver
O'Halloran, Palmer Dabbelt, Pedro Miraglia Franco de Carvalho, Philippe
Bergheaud, Pingfan Liu, Pratik Rajesh Sampat, Qian Cai, Qinglang Miao, Randy
Dunlap, Ravi Bangoria, Sachin Sant, Sam Bobroff, Sandipan Das, Santosh
Sivaraj, Satheesh Rajendran, Shirisha Ganta, Sourabh Jain, Srikar Dronamraju,
Stan Johnson, Stephen Rothwell, Thadeu Lima de Souza Cascardo, Thiago Jung
Bauermann, Tom Lane, Vaibhav Jain, Vladis Dronov, Wei Yongjun, Wen Xiong,
YueHaibing.
-----BEGIN PGP SIGNATURE-----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=QMY1
-----END PGP SIGNATURE-----
Merge tag 'powerpc-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
- Add support for (optionally) using queued spinlocks & rwlocks.
- Support for a new faster system call ABI using the scv instruction on
Power9 or later.
- Drop support for the PROT_SAO mmap/mprotect flag as it will be
unsupported on Power10 and future processors, leaving us with no way
to implement the functionality it requests. This risks breaking
userspace, though we believe it is unused in practice.
- A bug fix for, and then the removal of, our custom stack expansion
checking. We now allow stack expansion up to the rlimit, like other
architectures.
- Remove the remnants of our (previously disabled) topology update
code, which tried to react to NUMA layout changes on virtualised
systems, but was prone to crashes and other problems.
- Add PMU support for Power10 CPUs.
- A change to our signal trampoline so that we don't unbalance the link
stack (branch return predictor) in the signal delivery path.
- Lots of other cleanups, refactorings, smaller features and so on as
usual.
Thanks to: Abhishek Goel, Alastair D'Silva, Alexander A. Klimov, Alexey
Kardashevskiy, Alistair Popple, Andrew Donnellan, Aneesh Kumar K.V, Anju
T Sudhakar, Anton Blanchard, Arnd Bergmann, Athira Rajeev, Balamuruhan
S, Bharata B Rao, Bill Wendling, Bin Meng, Cédric Le Goater, Chris
Packham, Christophe Leroy, Christoph Hellwig, Daniel Axtens, Dan
Williams, David Lamparter, Desnes A. Nunes do Rosario, Erhard F., Finn
Thain, Frederic Barrat, Ganesh Goudar, Gautham R. Shenoy, Geoff Levand,
Greg Kurz, Gustavo A. R. Silva, Hari Bathini, Harish, Imre Kaloz, Joel
Stanley, Joe Perches, John Crispin, Jordan Niethe, Kajol Jain, Kamalesh
Babulal, Kees Cook, Laurent Dufour, Leonardo Bras, Li RongQing, Madhavan
Srinivasan, Mahesh Salgaonkar, Mark Cave-Ayland, Michal Suchanek, Milton
Miller, Mimi Zohar, Murilo Opsfelder Araujo, Nathan Chancellor, Nathan
Lynch, Naveen N. Rao, Nayna Jain, Nicholas Piggin, Oliver O'Halloran,
Palmer Dabbelt, Pedro Miraglia Franco de Carvalho, Philippe Bergheaud,
Pingfan Liu, Pratik Rajesh Sampat, Qian Cai, Qinglang Miao, Randy
Dunlap, Ravi Bangoria, Sachin Sant, Sam Bobroff, Sandipan Das, Santosh
Sivaraj, Satheesh Rajendran, Shirisha Ganta, Sourabh Jain, Srikar
Dronamraju, Stan Johnson, Stephen Rothwell, Thadeu Lima de Souza
Cascardo, Thiago Jung Bauermann, Tom Lane, Vaibhav Jain, Vladis Dronov,
Wei Yongjun, Wen Xiong, YueHaibing.
* tag 'powerpc-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (337 commits)
selftests/powerpc: Fix pkey syscall redefinitions
powerpc: Fix circular dependency between percpu.h and mmu.h
powerpc/powernv/sriov: Fix use of uninitialised variable
selftests/powerpc: Skip vmx/vsx/tar/etc tests on older CPUs
powerpc/40x: Fix assembler warning about r0
powerpc/papr_scm: Add support for fetching nvdimm 'fuel-gauge' metric
powerpc/papr_scm: Fetch nvdimm performance stats from PHYP
cpuidle: pseries: Fixup exit latency for CEDE(0)
cpuidle: pseries: Add function to parse extended CEDE records
cpuidle: pseries: Set the latency-hint before entering CEDE
selftests/powerpc: Fix online CPU selection
powerpc/perf: Consolidate perf_callchain_user_[64|32]()
powerpc/pseries/hotplug-cpu: Remove double free in error path
powerpc/pseries/mobility: Add pr_debug() for device tree changes
powerpc/pseries/mobility: Set pr_fmt()
powerpc/cacheinfo: Warn if cache object chain becomes unordered
powerpc/cacheinfo: Improve diagnostics about malformed cache lists
powerpc/cacheinfo: Use name@unit instead of full DT path in debug messages
powerpc/cacheinfo: Set pr_fmt()
powerpc: fix function annotations to avoid section mismatch warnings with gcc-10
...
Pull networking updates from David Miller:
1) Support 6Ghz band in ath11k driver, from Rajkumar Manoharan.
2) Support UDP segmentation in code TSO code, from Eric Dumazet.
3) Allow flashing different flash images in cxgb4 driver, from Vishal
Kulkarni.
4) Add drop frames counter and flow status to tc flower offloading,
from Po Liu.
5) Support n-tuple filters in cxgb4, from Vishal Kulkarni.
6) Various new indirect call avoidance, from Eric Dumazet and Brian
Vazquez.
7) Fix BPF verifier failures on 32-bit pointer arithmetic, from
Yonghong Song.
8) Support querying and setting hardware address of a port function via
devlink, use this in mlx5, from Parav Pandit.
9) Support hw ipsec offload on bonding slaves, from Jarod Wilson.
10) Switch qca8k driver over to phylink, from Jonathan McDowell.
11) In bpftool, show list of processes holding BPF FD references to
maps, programs, links, and btf objects. From Andrii Nakryiko.
12) Several conversions over to generic power management, from Vaibhav
Gupta.
13) Add support for SO_KEEPALIVE et al. to bpf_setsockopt(), from Dmitry
Yakunin.
14) Various https url conversions, from Alexander A. Klimov.
15) Timestamping and PHC support for mscc PHY driver, from Antoine
Tenart.
16) Support bpf iterating over tcp and udp sockets, from Yonghong Song.
17) Support 5GBASE-T i40e NICs, from Aleksandr Loktionov.
18) Add kTLS RX HW offload support to mlx5e, from Tariq Toukan.
19) Fix the ->ndo_start_xmit() return type to be netdev_tx_t in several
drivers. From Luc Van Oostenryck.
20) XDP support for xen-netfront, from Denis Kirjanov.
21) Support receive buffer autotuning in MPTCP, from Florian Westphal.
22) Support EF100 chip in sfc driver, from Edward Cree.
23) Add XDP support to mvpp2 driver, from Matteo Croce.
24) Support MPTCP in sock_diag, from Paolo Abeni.
25) Commonize UDP tunnel offloading code by creating udp_tunnel_nic
infrastructure, from Jakub Kicinski.
26) Several pci_ --> dma_ API conversions, from Christophe JAILLET.
27) Add FLOW_ACTION_POLICE support to mlxsw, from Ido Schimmel.
28) Add SK_LOOKUP bpf program type, from Jakub Sitnicki.
29) Refactor a lot of networking socket option handling code in order to
avoid set_fs() calls, from Christoph Hellwig.
30) Add rfc4884 support to icmp code, from Willem de Bruijn.
31) Support TBF offload in dpaa2-eth driver, from Ioana Ciornei.
32) Support XDP_REDIRECT in qede driver, from Alexander Lobakin.
33) Support PCI relaxed ordering in mlx5 driver, from Aya Levin.
34) Support TCP syncookies in MPTCP, from Flowian Westphal.
35) Fix several tricky cases of PMTU handling wrt. briding, from Stefano
Brivio.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2056 commits)
net: thunderx: initialize VF's mailbox mutex before first usage
usb: hso: remove bogus check for EINPROGRESS
usb: hso: no complaint about kmalloc failure
hso: fix bailout in error case of probe
ip_tunnel_core: Fix build for archs without _HAVE_ARCH_IPV6_CSUM
selftests/net: relax cpu affinity requirement in msg_zerocopy test
mptcp: be careful on subflow creation
selftests: rtnetlink: make kci_test_encap() return sub-test result
selftests: rtnetlink: correct the final return value for the test
net: dsa: sja1105: use detected device id instead of DT one on mismatch
tipc: set ub->ifindex for local ipv6 address
ipv6: add ipv6_dev_find()
net: openvswitch: silence suspicious RCU usage warning
Revert "vxlan: fix tos value before xmit"
ptp: only allow phase values lower than 1 period
farsync: switch from 'pci_' to 'dma_' API
wan: wanxl: switch from 'pci_' to 'dma_' API
hv_netvsc: do not use VF device if link is down
dpaa2-eth: Fix passing zero to 'PTR_ERR' warning
net: macb: Properly handle phylink on at91sam9x
...
This series adds reporting of the page table order from hmm_range_fault()
and some optimization of migrate_vma():
- Report the size of the page table mapping out of hmm_range_fault(). This
makes it easier to establish a large/huge/etc mapping in the device's
page table.
- Allow devices to ignore the invalidations during migration in cases
where the migration is not going to change pages. For instance migrating
pages to a device does not require the device to invalidate pages
already in the device.
- Update nouveau and hmm_tests to use the above
-----BEGIN PGP SIGNATURE-----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=omAU
-----END PGP SIGNATURE-----
Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
Pull hmm updates from Jason Gunthorpe:
"Ralph has been working on nouveau's use of hmm_range_fault() and
migrate_vma() which resulted in this small series. It adds reporting
of the page table order from hmm_range_fault() and some optimization
of migrate_vma():
- Report the size of the page table mapping out of hmm_range_fault().
This makes it easier to establish a large/huge/etc mapping in the
device's page table.
- Allow devices to ignore the invalidations during migration in cases
where the migration is not going to change pages.
For instance migrating pages to a device does not require the
device to invalidate pages already in the device.
- Update nouveau and hmm_tests to use the above"
* tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
mm/hmm/test: use the new migration invalidation
nouveau/svm: use the new migration invalidation
mm/notifier: add migration invalidation type
mm/migrate: add a flags parameter to migrate_vma
nouveau: fix storing invalid ptes
nouveau/hmm: support mapping large sysmem pages
nouveau: fix mapping 2MB sysmem pages
nouveau/hmm: fault one page at a time
mm/hmm: add tests for hmm_pfn_to_map_order()
mm/hmm: provide the page mapping order in hmm_range_fault()
while to come. Changes include:
- Some new Chinese translations
- Progress on the battle against double words words and non-HTTPS URLs
- Some block-mq documentation
- More RST conversions from Mauro. At this point, that task is
essentially complete, so we shouldn't see this kind of churn again for a
while. Unless we decide to switch to asciidoc or something...:)
- Lots of typo fixes, warning fixes, and more.
-----BEGIN PGP SIGNATURE-----
iQFDBAABCAAtFiEEIw+MvkEiF49krdp9F0NaE2wMflgFAl8oVkwPHGNvcmJldEBs
d24ubmV0AAoJEBdDWhNsDH5YoW8H/jJ/xnXFn7tkgVPQAlL3k5HCnK7A5nDP9RVR
cg1pTx1cEFdjzxPlJyExU6/v+AImOvtweHXC+JDK7YcJ6XFUNYXJI3LxL5KwUXbY
BL/xRFszDSXH2C7SJF5GECcFYp01e/FWSLN3yWAh+g+XwsKiTJ8q9+CoIDkHfPGO
7oQsHKFu6s36Af0LfSgxk4sVB7EJbo8e4psuPsP5SUrl+oXRO43Put0rXkR4yJoH
9oOaB51Do5fZp8I4JVAqGXvpXoExyLMO4yw0mASm6YSZ3KyjR8Fae+HD9Cq4ZuwY
0uzb9K+9NEhqbfwtyBsi99S64/6Zo/MonwKwevZuhtsDTK4l4iU=
=JQLZ
-----END PGP SIGNATURE-----
Merge tag 'docs-5.9' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"It's been a busy cycle for documentation - hopefully the busiest for a
while to come. Changes include:
- Some new Chinese translations
- Progress on the battle against double words words and non-HTTPS
URLs
- Some block-mq documentation
- More RST conversions from Mauro. At this point, that task is
essentially complete, so we shouldn't see this kind of churn again
for a while. Unless we decide to switch to asciidoc or
something...:)
- Lots of typo fixes, warning fixes, and more"
* tag 'docs-5.9' of git://git.lwn.net/linux: (195 commits)
scripts/kernel-doc: optionally treat warnings as errors
docs: ia64: correct typo
mailmap: add entry for <alobakin@marvell.com>
doc/zh_CN: add cpu-load Chinese version
Documentation/admin-guide: tainted-kernels: fix spelling mistake
MAINTAINERS: adjust kprobes.rst entry to new location
devices.txt: document rfkill allocation
PCI: correct flag name
docs: filesystems: vfs: correct flag name
docs: filesystems: vfs: correct sync_mode flag names
docs: path-lookup: markup fixes for emphasis
docs: path-lookup: more markup fixes
docs: path-lookup: fix HTML entity mojibake
CREDITS: Replace HTTP links with HTTPS ones
docs: process: Add an example for creating a fixes tag
doc/zh_CN: add Chinese translation prefer section
doc/zh_CN: add clearing-warn-once Chinese version
doc/zh_CN: add admin-guide index
doc:it_IT: process: coding-style.rst: Correct __maybe_unused compiler label
futex: MAINTAINERS: Re-add selftests directory
...
- Removal of the tremendously unpopular read_barrier_depends() barrier,
which is a NOP on all architectures apart from Alpha, in favour of
allowing architectures to override READ_ONCE() and do whatever dance
they need to do to ensure address dependencies provide LOAD ->
LOAD/STORE ordering. This work also offers a potential solution if
compilers are shown to convert LOAD -> LOAD address dependencies into
control dependencies (e.g. under LTO), as weakly ordered architectures
will effectively be able to upgrade READ_ONCE() to smp_load_acquire().
The latter case is not used yet, but will be discussed further at LPC.
- Make the MSI/IOMMU input/output ID translation PCI agnostic, augment
the MSI/IOMMU ACPI/OF ID mapping APIs to accept an input ID
bus-specific parameter and apply the resulting changes to the device
ID space provided by the Freescale FSL bus.
- arm64 support for TLBI range operations and translation table level
hints (part of the ARMv8.4 architecture version).
- Time namespace support for arm64.
- Export the virtual and physical address sizes in vmcoreinfo for
makedumpfile and crash utilities.
- CPU feature handling cleanups and checks for programmer errors
(overlapping bit-fields).
- ACPI updates for arm64: disallow AML accesses to EFI code regions and
kernel memory.
- perf updates for arm64.
- Miscellaneous fixes and cleanups, most notably PLT counting
optimisation for module loading, recordmcount fix to ignore
relocations other than R_AARCH64_CALL26, CMA areas reserved for
gigantic pages on 16K and 64K configurations.
- Trivial typos, duplicate words.
-----BEGIN PGP SIGNATURE-----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=mh79
-----END PGP SIGNATURE-----
Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 and cross-arch updates from Catalin Marinas:
"Here's a slightly wider-spread set of updates for 5.9.
Going outside the usual arch/arm64/ area is the removal of
read_barrier_depends() series from Will and the MSI/IOMMU ID
translation series from Lorenzo.
The notable arm64 updates include ARMv8.4 TLBI range operations and
translation level hint, time namespace support, and perf.
Summary:
- Removal of the tremendously unpopular read_barrier_depends()
barrier, which is a NOP on all architectures apart from Alpha, in
favour of allowing architectures to override READ_ONCE() and do
whatever dance they need to do to ensure address dependencies
provide LOAD -> LOAD/STORE ordering.
This work also offers a potential solution if compilers are shown
to convert LOAD -> LOAD address dependencies into control
dependencies (e.g. under LTO), as weakly ordered architectures will
effectively be able to upgrade READ_ONCE() to smp_load_acquire().
The latter case is not used yet, but will be discussed further at
LPC.
- Make the MSI/IOMMU input/output ID translation PCI agnostic,
augment the MSI/IOMMU ACPI/OF ID mapping APIs to accept an input ID
bus-specific parameter and apply the resulting changes to the
device ID space provided by the Freescale FSL bus.
- arm64 support for TLBI range operations and translation table level
hints (part of the ARMv8.4 architecture version).
- Time namespace support for arm64.
- Export the virtual and physical address sizes in vmcoreinfo for
makedumpfile and crash utilities.
- CPU feature handling cleanups and checks for programmer errors
(overlapping bit-fields).
- ACPI updates for arm64: disallow AML accesses to EFI code regions
and kernel memory.
- perf updates for arm64.
- Miscellaneous fixes and cleanups, most notably PLT counting
optimisation for module loading, recordmcount fix to ignore
relocations other than R_AARCH64_CALL26, CMA areas reserved for
gigantic pages on 16K and 64K configurations.
- Trivial typos, duplicate words"
Link: http://lkml.kernel.org/r/20200710165203.31284-1-will@kernel.org
Link: http://lkml.kernel.org/r/20200619082013.13661-1-lorenzo.pieralisi@arm.com
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (82 commits)
arm64: use IRQ_STACK_SIZE instead of THREAD_SIZE for irq stack
arm64/mm: save memory access in check_and_switch_context() fast switch path
arm64: sigcontext.h: delete duplicated word
arm64: ptrace.h: delete duplicated word
arm64: pgtable-hwdef.h: delete duplicated words
bus: fsl-mc: Add ACPI support for fsl-mc
bus/fsl-mc: Refactor the MSI domain creation in the DPRC driver
of/irq: Make of_msi_map_rid() PCI bus agnostic
of/irq: make of_msi_map_get_device_domain() bus agnostic
dt-bindings: arm: fsl: Add msi-map device-tree binding for fsl-mc bus
of/device: Add input id to of_dma_configure()
of/iommu: Make of_map_rid() PCI agnostic
ACPI/IORT: Add an input ID to acpi_dma_configure()
ACPI/IORT: Remove useless PCI bus walk
ACPI/IORT: Make iort_msi_map_rid() PCI agnostic
ACPI/IORT: Make iort_get_device_domain IRQ domain agnostic
ACPI/IORT: Make iort_match_node_callback walk the ACPI namespace for NC
arm64: enable time namespace support
arm64/vdso: Restrict splitting VVAR VMA
arm64/vdso: Handle faults on timens page
...
- Add support for custom exception handlers, as required by BPF_PROBE_MEM.
- Add support for BPF_PROBE_MEM.
- Add trace events for idle enter / exit for the s390 specific idle
implementation.
- Remove unused zcore memmmap device.
- Remove unused "raw view" from s390 debug feature.
- AP bus + zcrypt device driver code refactoring.
- Provide cex4 cca sysfs attributes for cex3 for zcrypt device driver.
- Expose only minimal interface to walk physmem for mm/memblock. This
is a common code change and it has been agreed on with Mike Rapoport
and Andrew Morton that this can go upstream via the s390 tree.
- Rework of the s390 vmem/vmmemap code to allow for future memory hot
remove.
- Get rid of FORCE_MAX_ZONEORDER to finally allow for order-10
allocations again, instead of only order-8 allocations.
- Various small improvements and fixes.
-----BEGIN PGP SIGNATURE-----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=H0KX
-----END PGP SIGNATURE-----
Merge tag 's390-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Heiko Carstens:
- Add support for function error injection.
- Add support for custom exception handlers, as required by
BPF_PROBE_MEM.
- Add support for BPF_PROBE_MEM.
- Add trace events for idle enter / exit for the s390 specific idle
implementation.
- Remove unused zcore memmmap device.
- Remove unused "raw view" from s390 debug feature.
- AP bus + zcrypt device driver code refactoring.
- Provide cex4 cca sysfs attributes for cex3 for zcrypt device driver.
- Expose only minimal interface to walk physmem for mm/memblock. This
is a common code change and it has been agreed on with Mike Rapoport
and Andrew Morton that this can go upstream via the s390 tree.
- Rework of the s390 vmem/vmmemap code to allow for future memory hot
remove.
- Get rid of FORCE_MAX_ZONEORDER to finally allow for order-10
allocations again, instead of only order-8 allocations.
- Various small improvements and fixes.
* tag 's390-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (48 commits)
s390/vmemmap: coding style updates
s390/vmemmap: avoid memset(PAGE_UNUSED) when adding consecutive sections
s390/vmemmap: remember unused sub-pmd ranges
s390/vmemmap: fallback to PTEs if mapping large PMD fails
s390/vmem: cleanup empty page tables
s390/vmemmap: take the vmem_mutex when populating/freeing
s390/vmemmap: cleanup when vmemmap_populate() fails
s390/vmemmap: extend modify_pagetable() to handle vmemmap
s390/vmem: consolidate vmem_add_range() and vmem_remove_range()
s390/vmem: rename vmem_add_mem() to vmem_add_range()
s390: enable HAVE_FUNCTION_ERROR_INJECTION
s390/pci: clarify comment in s390_mmio_read/write
s390/time: improve comparison for tod steering
s390/time: select CLOCKSOURCE_VALIDATE_LAST_CYCLE
s390/time: use CLOCKSOURCE_MASK
s390/bpf: implement BPF_PROBE_MEM
s390/kernel: expand exception table logic to allow new handling options
s390/kernel: unify EX_TABLE* implementations
s390/mm: allow order 10 allocations
s390/mm: avoid trimming to MAX_ORDER
...
-----BEGIN PGP SIGNATURE-----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=2vmy
-----END PGP SIGNATURE-----
Merge tag 'for-5.9/io_uring-20200802' of git://git.kernel.dk/linux-block
Pull io_uring updates from Jens Axboe:
"Lots of cleanups in here, hardening the code and/or making it easier
to read and fixing bugs, but a core feature/change too adding support
for real async buffered reads. With the latter in place, we just need
buffered write async support and we're done relying on kthreads for
the fast path. In detail:
- Cleanup how memory accounting is done on ring setup/free (Bijan)
- sq array offset calculation fixup (Dmitry)
- Consistently handle blocking off O_DIRECT submission path (me)
- Support proper async buffered reads, instead of relying on kthread
offload for that. This uses the page waitqueue to drive retries
from task_work, like we handle poll based retry. (me)
- IO completion optimizations (me)
- Fix race with accounting and ring fd install (me)
- Support EPOLLEXCLUSIVE (Jiufei)
- Get rid of the io_kiocb unionizing, made possible by shrinking
other bits (Pavel)
- Completion side cleanups (Pavel)
- Cleanup REQ_F_ flags handling, and kill off many of them (Pavel)
- Request environment grabbing cleanups (Pavel)
- File and socket read/write cleanups (Pavel)
- Improve kiocb_set_rw_flags() (Pavel)
- Tons of fixes and cleanups (Pavel)
- IORING_SQ_NEED_WAKEUP clear fix (Xiaoguang)"
* tag 'for-5.9/io_uring-20200802' of git://git.kernel.dk/linux-block: (127 commits)
io_uring: flip if handling after io_setup_async_rw
fs: optimise kiocb_set_rw_flags()
io_uring: don't touch 'ctx' after installing file descriptor
io_uring: get rid of atomic FAA for cq_timeouts
io_uring: consolidate *_check_overflow accounting
io_uring: fix stalled deferred requests
io_uring: fix racy overflow count reporting
io_uring: deduplicate __io_complete_rw()
io_uring: de-unionise io_kiocb
io-wq: update hash bits
io_uring: fix missing io_queue_linked_timeout()
io_uring: mark ->work uninitialised after cleanup
io_uring: deduplicate io_grab_files() calls
io_uring: don't do opcode prep twice
io_uring: clear IORING_SQ_NEED_WAKEUP after executing task works
io_uring: batch put_task_struct()
tasks: add put_task_struct_many()
io_uring: return locked and pinned page accounting
io_uring: don't miscount pinned memory
io_uring: don't open-code recv kbuf managment
...
-----BEGIN PGP SIGNATURE-----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=abJG
-----END PGP SIGNATURE-----
Merge tag 'for-5.9/block-20200802' of git://git.kernel.dk/linux-block
Pull core block updates from Jens Axboe:
"Good amount of cleanups and tech debt removals in here, and as a
result, the diffstat shows a nice net reduction in code.
- Softirq completion cleanups (Christoph)
- Stop using ->queuedata (Christoph)
- Cleanup bd claiming (Christoph)
- Use check_events, moving away from the legacy media change
(Christoph)
- Use inode i_blkbits consistently (Christoph)
- Remove old unused writeback congestion bits (Christoph)
- Cleanup/unify submission path (Christoph)
- Use bio_uninit consistently, instead of bio_disassociate_blkg
(Christoph)
- sbitmap cleared bits handling (John)
- Request merging blktrace event addition (Jan)
- sysfs add/remove race fixes (Luis)
- blk-mq tag fixes/optimizations (Ming)
- Duplicate words in comments (Randy)
- Flush deferral cleanup (Yufen)
- IO context locking/retry fixes (John)
- struct_size() usage (Gustavo)
- blk-iocost fixes (Chengming)
- blk-cgroup IO stats fixes (Boris)
- Various little fixes"
* tag 'for-5.9/block-20200802' of git://git.kernel.dk/linux-block: (135 commits)
block: blk-timeout: delete duplicated word
block: blk-mq-sched: delete duplicated word
block: blk-mq: delete duplicated word
block: genhd: delete duplicated words
block: elevator: delete duplicated word and fix typos
block: bio: delete duplicated words
block: bfq-iosched: fix duplicated word
iocost_monitor: start from the oldest usage index
iocost: Fix check condition of iocg abs_vdebt
block: Remove callback typedefs for blk_mq_ops
block: Use non _rcu version of list functions for tag_set_list
blk-cgroup: show global disk stats in root cgroup io.stat
blk-cgroup: make iostat functions visible to stat printing
block: improve discard bio alignment in __blkdev_issue_discard()
block: change REQ_OP_ZONE_RESET and REQ_OP_ZONE_RESET_ALL to be odd numbers
block: defer flush request no matter whether we have elevator
block: make blk_timeout_init() static
block: remove retry loop in ioc_release_fn()
block: remove unnecessary ioc nested locking
block: integrate bd_start_claiming into __blkdev_get
...
It turns out that wait_on_page_bit_common() had several problems,
ranging from just unfair behavioe due to re-queueing at the end of the
wait queue when re-trying, and an outright bug that could result in
missed wakeups (but probably never happened in practice).
This rewrites the whole logic to avoid both issues, by simply moving the
logic to check (and possibly take) the bit lock into the wakeup path
instead.
That makes everything much more straightforward, and means that we never
need to re-queue the wait entry: if we get woken up, we'll be notified
through WQ_FLAG_WOKEN, and the wait queue entry will have been removed,
and everything will have been done for us.
Link: https://lore.kernel.org/lkml/CAHk-=wjJA2Z3kUFb-5s=6+n0qbTs8ELqKFt9B3pH85a8fGD73w@mail.gmail.com/
Link: https://lore.kernel.org/lkml/alpine.LSU.2.11.2007221359450.1017@eggly.anvils/
Reported-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently migrate_vma_setup() calls mmu_notifier_invalidate_range_start()
which flushes all device private page mappings whether or not a page is
being migrated to/from device private memory.
In order to not disrupt device mappings that are not being migrated, shift
the responsibility for clearing device private mappings to the device
driver and leave CPU page table unmapping handled by
migrate_vma_setup().
To support this, the caller of migrate_vma_setup() should always set
struct migrate_vma::pgmap_owner to a non NULL value that matches the
device private page->pgmap->owner. This value is then passed to the struct
mmu_notifier_range with a new event type which the driver's invalidation
function can use to avoid device MMU invalidations.
Link: https://lore.kernel.org/r/20200723223004.9586-4-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
The src_owner field in struct migrate_vma is being used for two purposes,
it acts as a selection filter for which types of pages are to be migrated
and it identifies device private pages owned by the caller.
Split this into separate parameters so the src_owner field can be used
just to identify device private pages owned by the caller of
migrate_vma_setup().
Rename the src_owner field to pgmap_owner to reflect it is now used only
to identify which device private pages to migrate.
Link: https://lore.kernel.org/r/20200723223004.9586-3-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
The UDP reuseport conflict was a little bit tricky.
The net-next code, via bpf-next, extracted the reuseport handling
into a helper so that the BPF sk lookup code could invoke it.
At the same time, the logic for reuseport handling of unconnected
sockets changed via commit efc6b6f6c3
which changed the logic to carry on the reuseport result into the
rest of the lookup loop if we do not return immediately.
This requires moving the reuseport_has_conns() logic into the callers.
While we are here, get rid of inline directives as they do not belong
in foo.c files.
The other changes were cases of more straightforward overlapping
modifications.
Signed-off-by: David S. Miller <davem@davemloft.net>
khugepaged has to drop mmap lock several times while collapsing a page.
The situation can change while the lock is dropped and we need to
re-validate that the VMA is still in place and the PMD is still subject
for collapse.
But we miss one corner case: while collapsing an anonymous pages the VMA
could be replaced with file VMA. If the file VMA doesn't have any
private pages we get NULL pointer dereference:
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
anon_vma_lock_write include/linux/rmap.h:120 [inline]
collapse_huge_page mm/khugepaged.c:1110 [inline]
khugepaged_scan_pmd mm/khugepaged.c:1349 [inline]
khugepaged_scan_mm_slot mm/khugepaged.c:2110 [inline]
khugepaged_do_scan mm/khugepaged.c:2193 [inline]
khugepaged+0x3bba/0x5a10 mm/khugepaged.c:2238
The fix is to make sure that the VMA is anonymous in
hugepage_vma_revalidate(). The helper is only used for collapsing
anonymous pages.
Fixes: 99cb0dbd47 ("mm,thp: add read-only THP support for (non-shmem) FS")
Reported-by: syzbot+ed318e8b790ca72c5ad0@syzkaller.appspotmail.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Yang Shi <yang.shi@linux.alibaba.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200722121439.44328-1-kirill.shutemov@linux.intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hugetlb_cma[0] can be NULL due to various reasons, for example, node0
has no memory. so NULL hugetlb_cma[0] doesn't necessarily mean cma is
not enabled. gigantic pages might have been reserved on other nodes.
This patch fixes possible double reservation and CMA leak.
[akpm@linux-foundation.org: fix CONFIG_CMA=n warning]
[sfr@canb.auug.org.au: better checks before using hugetlb_cma]
Link: http://lkml.kernel.org/r/20200721205716.6dbaa56b@canb.auug.org.au
Fixes: cf11e85fc0 ("mm: hugetlb: optionally allocate gigantic hugepages using cma")
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200710005726.36068-1-song.bao.hua@hisilicon.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the kmem_cache refcount is greater than one, we should not mark the
root kmem_cache as dying. If we mark the root kmem_cache dying
incorrectly, the non-root kmem_cache can never be destroyed. It
resulted in memory leak when memcg was destroyed. We can use the
following steps to reproduce.
1) Use kmem_cache_create() to create a new kmem_cache named A.
2) Coincidentally, the kmem_cache A is an alias for kmem_cache B,
so the refcount of B is just increased.
3) Use kmem_cache_destroy() to destroy the kmem_cache A, just
decrease the B's refcount but mark the B as dying.
4) Create a new memory cgroup and alloc memory from the kmem_cache
B. It leads to create a non-root kmem_cache for allocating memory.
5) When destroy the memory cgroup created in the step 4), the
non-root kmem_cache can never be destroyed.
If we repeat steps 4) and 5), this will cause a lot of memory leak. So
only when refcount reach zero, we mark the root kmem_cache as dying.
Fixes: 92ee383f6d ("mm: fix race between kmem_cache destroy, create and deactivate")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200716165103.83462-1-songmuchun@bytedance.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It was hard to keep a test running, moving tasks between memcgs with
move_charge_at_immigrate, while swapping: mem_cgroup_id_get_many()'s
refcount is discovered to be 0 (supposedly impossible), so it is then
forced to REFCOUNT_SATURATED, and after thousands of warnings in quick
succession, the test is at last put out of misery by being OOM killed.
This is because of the way moved_swap accounting was saved up until the
task move gets completed in __mem_cgroup_clear_mc(), deferred from when
mem_cgroup_move_swap_account() actually exchanged old and new ids.
Concurrent activity can free up swap quicker than the task is scanned,
bringing id refcount down 0 (which should only be possible when
offlining).
Just skip that optimization: do that part of the accounting immediately.
Fixes: 615d66c37c ("mm: memcontrol: fix memcg id ref counter on swap charge move")
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2007071431050.4726@eggly.anvils
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Prabhakar reported an OOPS inside mem_cgroup_get_nr_swap_pages()
function in a corner case seen on some arm64 boards when kdump kernel
runs with "cgroup_disable=memory" passed to the kdump kernel via
bootargs.
The root-cause behind the same is that currently mem_cgroup_swap_init()
function is implemented as a subsys_initcall() call instead of a
core_initcall(), this means 'cgroup_memory_noswap' still remains set to
the default value (false) even when memcg is disabled via
"cgroup_disable=memory" boot parameter.
This may result in premature OOPS inside mem_cgroup_get_nr_swap_pages()
function in corner cases:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000188
Mem abort info:
ESR = 0x96000006
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
Data abort info:
ISV = 0, ISS = 0x00000006
CM = 0, WnR = 0
[0000000000000188] user address but active_mm is swapper
Internal error: Oops: 96000006 [#1] SMP
Modules linked in:
<..snip..>
Call trace:
mem_cgroup_get_nr_swap_pages+0x9c/0xf4
shrink_lruvec+0x404/0x4f8
shrink_node+0x1a8/0x688
do_try_to_free_pages+0xe8/0x448
try_to_free_pages+0x110/0x230
__alloc_pages_slowpath.constprop.106+0x2b8/0xb48
__alloc_pages_nodemask+0x2ac/0x2f8
alloc_page_interleave+0x20/0x90
alloc_pages_current+0xdc/0xf8
atomic_pool_expand+0x60/0x210
__dma_atomic_pool_init+0x50/0xa4
dma_atomic_pool_init+0xac/0x158
do_one_initcall+0x50/0x218
kernel_init_freeable+0x22c/0x2d0
kernel_init+0x18/0x110
ret_from_fork+0x10/0x18
Code: aa1403e3 91106000 97f82a27 14000011 (f940c663)
---[ end trace 9795948475817de4 ]---
Kernel panic - not syncing: Fatal exception
Rebooting in 10 seconds..
Fixes: eccb52e788 ("mm: memcontrol: prepare swap controller setup for integration")
Reported-by: Prabhakar Kushwaha <pkushwaha@marvell.com>
Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: James Morse <james.morse@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Link: http://lkml.kernel.org/r/1593641660-13254-2-git-send-email-bhsharma@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
clang static analysis reports a garbage return
In file included from mm/memory.c:84:
mm/memory.c:1612:2: warning: Undefined or garbage value returned to caller [core.uninitialized.UndefReturn]
return err;
^~~~~~~~~~
The setting of err depends on a loop executing. So initialize err.
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200703155354.29132-1-trix@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After commit fdc85222d5 ("kernfs: kvmalloc xattr value instead of
kmalloc"), simple xattr entry is allocated with kvmalloc() instead of
kmalloc(), so we should release it with kvfree() instead of kfree().
Fixes: fdc85222d5 ("kernfs: kvmalloc xattr value instead of kmalloc")
Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Daniel Xu <dxu@dxuuu.xyz>
Cc: Chris Down <chris@chrisdown.name>
Cc: Andreas Dilger <adilger@dilger.ca>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org> [5.7]
Link: http://lkml.kernel.org/r/20200704051608.15043-1-cgxu519@mykernel.net
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
VMA with VM_GROWSDOWN or VM_GROWSUP flag set can change their size under
mmap_read_lock(). It can lead to race with __do_munmap():
Thread A Thread B
__do_munmap()
detach_vmas_to_be_unmapped()
mmap_write_downgrade()
expand_downwards()
vma->vm_start = address;
// The VMA now overlaps with
// VMAs detached by the Thread A
// page fault populates expanded part
// of the VMA
unmap_region()
// Zaps pagetables partly
// populated by Thread B
Similar race exists for expand_upwards().
The fix is to avoid downgrading mmap_lock in __do_munmap() if detached
VMAs are next to VM_GROWSDOWN or VM_GROWSUP VMA.
[akpm@linux-foundation.org: s/mmap_sem/mmap_lock/ in comment]
Fixes: dd2283f260 ("mm: mmap: zap pages with read mmap_sem in munmap")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Yang Shi <yang.shi@linux.alibaba.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org> [4.20+]
Link: http://lkml.kernel.org/r/20200709105309.42495-1-kirill.shutemov@linux.intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ISA v3.1 does not support the SAO storage control attribute required to
implement PROT_SAO. PROT_SAO was used by specialised system software
(Lx86) that has been discontinued for about 7 years, and is not thought
to be used elsewhere, so removal should not cause problems.
We rather remove it than keep support for older processors, because
live migrating guest partitions to newer processors may not be possible
if SAO is in use (or worse allowed with silent races).
- PROT_SAO stays in the uapi header so code using it would still build.
- arch_validate_prot() is removed, the generic version rejects PROT_SAO
so applications would get a failure at mmap() time.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Drop KVM change for the time being]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200703011958.1166620-3-npiggin@gmail.com
In preparation for removing smp_read_barrier_depends() altogether,
move the Alpha code over to using smp_rmb() and smp_mb() directly.
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.
In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:
git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
xargs perl -pi -e \
's/\buninitialized_var\(([^\)]+)\)/\1/g;
s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'
drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.
No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.
[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/
Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>
Naresh Kamboju reported that the LTP tests can cause warnings on i386
going back all the way to v5.0, and bisected it to commit 2c91bd4a4e
("mm: speed up mremap by 20x on large regions").
The warning in move_normal_pmd() is actually mostly correct, but we have
a very unusual special case at process creation time, when we may move
the stack down with an overlapping mode (kind of like a "memmove()"
except using the page tables).
And when you have just the right condition of "move a large initial
stack by the right alignment in the end, but with the early part of the
move being only page-aligned", we'll be in a situation where we're
trying to move a normal PMD entry on top of an already existing - but
now empty - PMD entry.
The warning is still worth having, in case it ever triggers other cases,
and perhaps as a reminder that we could do the stack move case more
efficiently (although it's clearly rare enough that it probably doesn't
matter).
But make it do WARN_ON_ONCE(), so that you can't flood the logs with it.
And add a *big* comment above it to explain and remind us what's going
on, because it took some figuring out to see how this could trigger.
Kudos to Joel Fernandes for debugging this.
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Debugged-and-acked-by: Joel Fernandes <joel@joelfernandes.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
debugfs_create_u32_array() allocates a small structure to wrap
the data and size information about the array. If users ever
try to remove the file this leads to a leak since nothing ever
frees this wrapper.
That said there are no upstream users of debugfs_create_u32_array()
that'd remove a u32 array file (we only have one u32 array user in
CMA), so there is no real bug here.
Make callers pass a wrapper they allocated. This way the lifetime
management of the wrapper is on the caller, and we can avoid the
potential leak in debugfs.
CC: Chucheng Luo <luochucheng@vivo.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
hmm_range_fault() returns an array of page frame numbers and flags for how
the pages are mapped in the requested process' page tables. The PFN can be
used to get the struct page with hmm_pfn_to_page() and the page size order
can be determined with compound_order(page).
However, if the page is larger than order 0 (PAGE_SIZE), there is no
indication that a compound page is mapped by the CPU using a larger page
size. Without this information, the caller can't safely use a large device
PTE to map the compound page because the CPU might be using smaller PTEs
with different read/write permissions.
Add a new function hmm_pfn_to_map_order() to return the mapping size order
so that callers know the pages are being mapped with consistent
permissions and a large device page table mapping can be used if one is
available.
This will allow devices to optimize mapping the page into HW by avoiding
or batching work for huge pages. For instance the dma_map can be done with
a high order directly.
Link: https://lore.kernel.org/r/20200701225352.9649-3-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
-----BEGIN PGP SIGNATURE-----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=dfnJ
-----END PGP SIGNATURE-----
Merge tag 'gfs2-v5.8-rc4.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2
Pull gfs2 fixes from Andreas Gruenbacher:
"Fix gfs2 readahead deadlocks by adding a IOCB_NOIO flag that allows
gfs2 to use the generic fiel read iterator functions without having to
worry about being called back while holding locks".
* tag 'gfs2-v5.8-rc4.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
gfs2: Rework read and page fault locking
fs: Add IOCB_NOIO flag for generic_file_read_iter
"physmem" in the memblock allocator is somewhat weird: it's not actually
used for allocation, it's simply information collected during boot, which
describes the unmodified physical memory map at boot time, without any
standby/hotplugged memory. It's only used on s390 and is currently the
only reason s390 keeps using CONFIG_ARCH_KEEP_MEMBLOCK.
Physmem isn't numa aware and current users don't specify any flags. Let's
hide it from the user, exposing only for_each_physmem(), and simplify. The
interface for physmem is now really minimalistic:
- memblock_physmem_add() to add ranges
- for_each_physmem() / __next_physmem_range() to walk physmem ranges
Don't place it into an __init section and don't discard it without
CONFIG_ARCH_KEEP_MEMBLOCK. As we're reusing __next_mem_range(), remove
the __meminit notifier to avoid section mismatch warnings once
CONFIG_ARCH_KEEP_MEMBLOCK is no longer used with
CONFIG_HAVE_MEMBLOCK_PHYS_MAP.
While fixing up the documentation, sneak in some related cleanups. We can
stop setting CONFIG_ARCH_KEEP_MEMBLOCK for s390 next.
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Message-Id: <20200701141830.18749-2-david@redhat.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
We never set any congested bits in the group writeback instances of it.
And for the simpler bdi-wide case a simple scalar field is all that
that is needed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
I realize that we fairly recently raised it to 4.8, but the fact is, 4.9
is a much better minimum version to target.
We have a number of workarounds for actual bugs in pre-4.9 gcc versions
(including things like internal compiler errors on ARM), but we also
have some syntactic workarounds for lacking features.
In particular, raising the minimum to 4.9 means that we can now just
assume _Generic() exists, which is likely the much better replacement
for a lot of very convoluted built-time magic with conditionals on
sizeof and/or __builtin_choose_expr() with same_type() etc.
Using _Generic also means that you will need to have a very recent
version of 'sparse', but thats easy to build yourself, and much less of
a hassle than some old gcc version can be.
The latest (in a long string) of reasons for minimum compiler version
upgrades was commit 5435f73d5c ("efi/x86: Fix build with gcc 4").
Ard points out that RHEL 7 uses gcc-4.8, but the people who stay back on
old RHEL versions persumably also don't build their own kernels anyway.
And maybe they should cross-built or just have a little side affair with
a newer compiler?
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add an IOCB_NOIO flag that indicates to generic_file_read_iter that it
shouldn't trigger any filesystem I/O for the actual request or for
readahead. This allows to do tentative reads out of the page cache as
some filesystems allow, and to take the appropriate locks and retry the
reads only if the requested pages are not cached.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Some Makefiles already pass -fno-stack-protector unconditionally.
For example, arch/arm64/kernel/vdso/Makefile, arch/x86/xen/Makefile.
No problem report so far about hard-coding this option. So, we can
assume all supported compilers know -fno-stack-protector.
GCC 4.8 and Clang support this option (https://godbolt.org/z/_HDGzN)
Get rid of cc-option from -fno-stack-protector.
Remove CONFIG_CC_HAS_STACKPROTECTOR_NONE, which is always 'y'.
Note:
arch/mips/vdso/Makefile adds -fno-stack-protector twice, first
unconditionally, and second conditionally. I removed the second one.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
When I increased the upper bound of the min_free_kbytes value in
ee8eb9a5fe ("mm/page_alloc: increase default min_free_kbytes bound") I
forgot to tweak the above comment to reflect the new value. This patch
fixes that mistake.
Signed-off-by: Joel Savitz <jsavitz@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Fabrizio D'Angelo <fdangelo@redhat.com>
Link: http://lkml.kernel.org/r/20200624221236.29560-1-jsavitz@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Calling cma_declare_contiguous_nid() with false exact_nid for per-numa
reservation can easily cause cma leak and various confusion. For example,
mm/hugetlb.c is trying to reserve per-numa cma for gigantic pages. But it
can easily leak cma and make users confused when system has memoryless
nodes.
In case the system has 4 numa nodes, and only numa node0 has memory. if
we set hugetlb_cma=4G in bootargs, mm/hugetlb.c will get 4 cma areas for 4
different numa nodes. since exact_nid=false in current code, all 4 numa
nodes will get cma successfully from node0, but hugetlb_cma[1 to 3] will
never be available to hugepage will only allocate memory from
hugetlb_cma[0].
In case the system has 4 numa nodes, both numa node0&2 has memory, other
nodes have no memory. if we set hugetlb_cma=4G in bootargs, mm/hugetlb.c
will get 4 cma areas for 4 different numa nodes. since exact_nid=false in
current code, all 4 numa nodes will get cma successfully from node0 or 2,
but hugetlb_cma[1] and [3] will never be available to hugepage as
mm/hugetlb.c will only allocate memory from hugetlb_cma[0] and
hugetlb_cma[2]. This causes permanent leak of the cma areas which are
supposed to be used by memoryless node.
Of cource we can workaround the issue by letting mm/hugetlb.c scan all cma
areas in alloc_gigantic_page() even node_mask includes node0 only. that
means when node_mask includes node0 only, we can get page from
hugetlb_cma[1] to hugetlb_cma[3]. But this will cause kernel crash in
free_gigantic_page() while it wants to free page by:
cma_release(hugetlb_cma[page_to_nid(page)], page, 1 << order)
On the other hand, exact_nid=false won't consider numa distance, it might
be not that useful to leverage cma areas on remote nodes. I feel it is
much simpler to make exact_nid true to make everything clear. After that,
memoryless nodes won't be able to reserve per-numa CMA from other nodes
which have memory.
Fixes: cf11e85fc0 ("mm: hugetlb: optionally allocate gigantic hugepages using cma")
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Aslan Bakirov <aslan@fb.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Andreas Schaufler <andreas.schaufler@gmx.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200628074345.27228-1-song.bao.hua@hisilicon.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The routine hpage_nr_pages() was incorrectly used to calculate the number
of base pages in a hugetlb page. hpage_nr_pages is designed to be called
for THP pages and will return HPAGE_PMD_NR for hugetlb pages of any size.
Due to the context in which hpage_nr_pages was called, it is unlikely to
produce a user visible error. The routine with the incorrect call is only
exercised in the case of hugetlb memory error or migration. In addition,
this would need to be on an architecture which supports huge page sizes
less than PMD_SIZE. And, the vma containing the huge page would also need
to smaller than PMD_SIZE.
Fixes: c0d0381ade ("hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronization")
Reported-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200629185003.97202-1-mike.kravetz@oracle.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Just use bd_disk->queue instead.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Rename kvfree_rcu() function to the kvfree_rcu_local() one.
The purpose is to prevent a conflict of two same function
declarations. The kvfree_rcu() will be globally visible
what would lead to a build error. No functional change.
Cc: linux-mm@kvack.org
Cc: rcu@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
bio_associate_blkg_from_page is a special purpose helper for swap bios
that doesn't need access to bio internals. Move it to the swap code
instead of having it in bio.c.
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The nommu-mmap.txt file provides description of user visible
behaviuour. So, move it to the admin-guide.
As it is already at the ReST, also rename it.
Suggested-by: Mike Rapoport <rppt@linux.ibm.com>
Suggested-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/3a63d1833b513700755c85bf3bda0a6c4ab56986.1592918949.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
When working with very large nodes, poisoning the struct pages (for which
there will be very many) can take a very long time. If the system is
using voluntary preemptions, the software watchdog will not be able to
detect forward progress. This patch addresses this issue by offering to
give up time like __remove_pages() does. This behavior was introduced in
v5.6 with: commit d33695b16a ("mm/memory_hotplug: poison memmap in
remove_pfn_range_from_zone()")
Alternately, init_page_poison could do this cond_resched(), but it seems
to me that the caller of init_page_poison() is what actually knows whether
or not it should relax its own priority.
Based on Dan's notes, I think this is perfectly safe: commit f931ab479d
("mm: fix devm_memremap_pages crash, use mem_hotplug_{begin, done}")
Aside from fixing the lockup, it is also a friendlier thing to do on lower
core systems that might wipe out large chunks of hotplug memory (probably
not a very common case).
Fixes this kind of splat:
watchdog: BUG: soft lockup - CPU#46 stuck for 22s! [daxctl:9922]
irq event stamp: 138450
hardirqs last enabled at (138449): [<ffffffffa1001f26>] trace_hardirqs_on_thunk+0x1a/0x1c
hardirqs last disabled at (138450): [<ffffffffa1001f42>] trace_hardirqs_off_thunk+0x1a/0x1c
softirqs last enabled at (138448): [<ffffffffa1e00347>] __do_softirq+0x347/0x456
softirqs last disabled at (138443): [<ffffffffa10c416d>] irq_exit+0x7d/0xb0
CPU: 46 PID: 9922 Comm: daxctl Not tainted 5.7.0-BEN-14238-g373c6049b336 #30
Hardware name: Intel Corporation PURLEY/PURLEY, BIOS PLYXCRB1.86B.0578.D07.1902280810 02/28/2019
RIP: 0010:memset_erms+0x9/0x10
Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 <f3> aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01
Call Trace:
remove_pfn_range_from_zone+0x3a/0x380
memunmap_pages+0x17f/0x280
release_nodes+0x22a/0x260
__device_release_driver+0x172/0x220
device_driver_detach+0x3e/0xa0
unbind_store+0x113/0x130
kernfs_fop_write+0xdc/0x1c0
vfs_write+0xde/0x1d0
ksys_write+0x58/0xd0
do_syscall_64+0x5a/0x120
entry_SYSCALL_64_after_hwframe+0x49/0xb3
Built 2 zonelists, mobility grouping on. Total pages: 49050381
Policy zone: Normal
Built 3 zonelists, mobility grouping on. Total pages: 49312525
Policy zone: Normal
David said: "It really only is an issue for devmem. Ordinary
hotplugged system memory is not affected (onlined/offlined in memory
block granularity)."
Link: http://lkml.kernel.org/r/20200619231213.1160351-1-ben.widawsky@intel.com
Fixes: commit d33695b16a ("mm/memory_hotplug: poison memmap in remove_pfn_range_from_zone()")
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Reported-by: "Scargall, Steve" <steve.scargall@intel.com>
Reported-by: Ben Widawsky <ben.widawsky@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge vmalloc_exec into its only caller. Note that for !CONFIG_MMU
__vmalloc_node_range maps to __vmalloc, which directly clears the
__GFP_HIGHMEM added by the vmalloc_exec stub anyway.
Link: http://lkml.kernel.org/r/20200618064307.32739-4-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With synchronous IO swap device, swap-in is directly handled in fault
code. Since IO cost notation isn't added there, with synchronous IO
swap device, LRU balancing could be wrongly biased. Fix it to count it
in fault code.
Link: http://lkml.kernel.org/r/1592288204-27734-4-git-send-email-iamjoonsoo.kim@lge.com
Fixes: 314b57fb04 ("mm: balance LRU lists based on relative thrashing cache sizing")
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Non-file-lru page could also be activated in mark_page_accessed() and we
need to count this activation for nonresident_age.
Note that it's better for this patch to be squashed into the patch "mm:
workingset: age nonresident information alongside anonymous pages".
Link: http://lkml.kernel.org/r/1592288204-27734-3-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "fix for "mm: balance LRU lists based on relative
thrashing" patchset"
This patchset fixes some problems of the patchset, "mm: balance LRU
lists based on relative thrashing", which is now merged on the mainline.
Patch "mm: workingset: let cache workingset challenge anon fix" is the
result of discussion with Johannes. See following link.
http://lkml.kernel.org/r/20200520232525.798933-6-hannes@cmpxchg.org
And, the other two are minor things which are found when I try to rebase
my patchset.
This patch (of 3):
After ("mm: workingset: let cache workingset challenge anon fix"), we
compare refault distances to active_file + anon. But age of the
non-resident information is only driven by the file LRU. As a result,
we may overestimate the recency of any incoming refaults and activate
them too eagerly, causing unnecessary LRU churn in certain situations.
Make anon aging drive nonresident age as well to address that.
Link: http://lkml.kernel.org/r/1592288204-27734-1-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1592288204-27734-2-git-send-email-iamjoonsoo.kim@lge.com
Fixes: 34e58cac6d ("mm: workingset: let cache workingset challenge anon")
Reported-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Looks like one of these got missed when massaging in f86b810c26 ("mm,
memcg: prevent memory.low load/store tearing") with other linux-mm
changes.
Link: http://lkml.kernel.org/r/20200612174437.GA391453@chrisdown.name
Signed-off-by: Chris Down <chris@chrisdown.name>
Reported-by: Michal Koutny <mkoutny@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We should put the css reference when memory allocation failed.
Link: http://lkml.kernel.org/r/20200614122653.98829-1-songmuchun@bytedance.com
Fixes: f0a3a24b53 ("mm: memcg/slab: rework non-root kmem_cache lifecycle management")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tejun reports seeing rare div0 crashes in memory.low stress testing:
RIP: 0010:mem_cgroup_calculate_protection+0xed/0x150
Code: 0f 46 d1 4c 39 d8 72 57 f6 05 16 d6 42 01 40 74 1f 4c 39 d8 76 1a 4c 39 d1 76 15 4c 29 d1 4c 29 d8 4d 29 d9 31 d2 48 0f af c1 <49> f7 f1 49 01 c2 4c 89 96 38 01 00 00 5d c3 48 0f af c7 31 d2 49
RSP: 0018:ffffa14e01d6fcd0 EFLAGS: 00010246
RAX: 000000000243e384 RBX: 0000000000000000 RCX: 0000000000008f4b
RDX: 0000000000000000 RSI: ffff8b89bee84000 RDI: 0000000000000000
RBP: ffffa14e01d6fcd0 R08: ffff8b89ca7d40f8 R09: 0000000000000000
R10: 0000000000000000 R11: 00000000006422f7 R12: 0000000000000000
R13: ffff8b89d9617000 R14: ffff8b89bee84000 R15: ffffa14e01d6fdb8
FS: 0000000000000000(0000) GS:ffff8b8a1f1c0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f93b1fc175b CR3: 000000016100a000 CR4: 0000000000340ea0
Call Trace:
shrink_node+0x1e5/0x6c0
balance_pgdat+0x32d/0x5f0
kswapd+0x1d7/0x3d0
kthread+0x11c/0x160
ret_from_fork+0x1f/0x30
This happens when parent_usage == siblings_protected.
We check that usage is bigger than protected, which should imply
parent_usage being bigger than siblings_protected. However, we don't
read (or even update) these values atomically, and they can be out of
sync as the memory state changes under us. A bit of fluctuation around
the target protection isn't a big deal, but we need to handle the div0
case.
Check the parent state explicitly to make sure we have a reasonable
positive value for the divisor.
Link: http://lkml.kernel.org/r/20200615140658.601684-1-hannes@cmpxchg.org
Fixes: 8a931f8013 ("mm: memcontrol: recursive memory.low protection")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Tejun Heo <tj@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Chris Down <chris@chrisdown.name>
Cc: Roman Gushchin <guro@fb.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes following warning while "make xmldocs"
mm/vmalloc.c:1877: warning: Excess function parameter 'prot' description in 'vm_map_ram'
This warning started since commit d4efd79a81 ("mm: remove the prot
argument from vm_map_ram").
Link: http://lkml.kernel.org/r/20200622152850.140871-1-standby24x7@gmail.com
Fixes: d4efd79a81 ("mm: remove the prot argument from vm_map_ram")
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit 9e343b467c ("READ_ONCE: Enforce atomicity for
{READ,WRITE}_ONCE() memory accesses"), READ_ONCE() cannot be used
anymore to read complex page table entries.
This leads to:
CC mm/debug_vm_pgtable.o
In file included from ./include/asm-generic/bug.h:5,
from ./arch/powerpc/include/asm/bug.h:109,
from ./include/linux/bug.h:5,
from ./include/linux/mmdebug.h:5,
from ./include/linux/gfp.h:5,
from mm/debug_vm_pgtable.c:13:
In function 'pte_clear_tests',
inlined from 'debug_vm_pgtable' at mm/debug_vm_pgtable.c:363:2:
./include/linux/compiler.h:392:38: error: Unsupported access size for {READ,WRITE}_ONCE().
mm/debug_vm_pgtable.c:249:14: note: in expansion of macro 'READ_ONCE'
249 | pte_t pte = READ_ONCE(*ptep);
| ^~~~~~~~~
make[2]: *** [mm/debug_vm_pgtable.o] Error 1
Fix it by using the recently added ptep_get() helper.
Link: http://lkml.kernel.org/r/6ca8c972e6c920dc4ae0d4affbed9703afa4d010.1592490570.git.christophe.leroy@csgroup.eu
Fixes: 9e343b467c ("READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Calls to pte_offset_map() in vm_insert_pages() are erroneously not
matched with a call to pte_unmap(). This would cause problems on
architectures where that is not a no-op.
This patch does away with the non-traditional locking in the existing
code, and instead uses pte_offset_map_lock/unlock() as usual,
incrementing PTE as necessary. The PTE pointer is kept within bounds
since we clamp it with PTRS_PER_PTE.
Link: http://lkml.kernel.org/r/20200618220446.20284-1-arjunroy.kdev@gmail.com
Fixes: 8cd3984d81 ("mm/memory.c: add vm_insert_pages()")
Signed-off-by: Arjun Roy <arjunroy@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Chris Murphy reports that a slightly overcommitted load, testing swap
and zram along with i915, splats and keeps on splatting, when it had
better fail less noisily:
gnome-shell: page allocation failure: order:0,
mode:0x400d0(__GFP_IO|__GFP_FS|__GFP_COMP|__GFP_RECLAIMABLE),
nodemask=(null),cpuset=/,mems_allowed=0
CPU: 2 PID: 1155 Comm: gnome-shell Not tainted 5.7.0-1.fc33.x86_64 #1
Call Trace:
dump_stack+0x64/0x88
warn_alloc.cold+0x75/0xd9
__alloc_pages_slowpath.constprop.0+0xcfa/0xd30
__alloc_pages_nodemask+0x2df/0x320
alloc_slab_page+0x195/0x310
allocate_slab+0x3c5/0x440
___slab_alloc+0x40c/0x5f0
__slab_alloc+0x1c/0x30
kmem_cache_alloc+0x20e/0x220
xas_nomem+0x28/0x70
add_to_swap_cache+0x321/0x400
__read_swap_cache_async+0x105/0x240
swap_cluster_readahead+0x22c/0x2e0
shmem_swapin+0x8e/0xc0
shmem_swapin_page+0x196/0x740
shmem_getpage_gfp+0x3a2/0xa60
shmem_read_mapping_page_gfp+0x32/0x60
shmem_get_pages+0x155/0x5e0 [i915]
__i915_gem_object_get_pages+0x68/0xa0 [i915]
i915_vma_pin+0x3fe/0x6c0 [i915]
eb_add_vma+0x10b/0x2c0 [i915]
i915_gem_do_execbuffer+0x704/0x3430 [i915]
i915_gem_execbuffer2_ioctl+0x1ea/0x3e0 [i915]
drm_ioctl_kernel+0x86/0xd0 [drm]
drm_ioctl+0x206/0x390 [drm]
ksys_ioctl+0x82/0xc0
__x64_sys_ioctl+0x16/0x20
do_syscall_64+0x5b/0xf0
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Reported on 5.7, but it goes back really to 3.1: when
shmem_read_mapping_page_gfp() was implemented for use by i915, and
allowed for __GFP_NORETRY and __GFP_NOWARN flags in most places, but
missed swapin's "& GFP_KERNEL" mask for page tree node allocation in
__read_swap_cache_async() - that was to mask off HIGHUSER_MOVABLE bits
from what page cache uses, but GFP_RECLAIM_MASK is now what's needed.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=208085
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2006151330070.11064@eggly.anvils
Fixes: 68da9f0557 ("tmpfs: pass gfp to shmem_getpage_gfp")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: Chris Murphy <lists@colorremedies.com>
Analyzed-by: Vlastimil Babka <vbabka@suse.cz>
Analyzed-by: Matthew Wilcox <willy@infradead.org>
Tested-by: Chris Murphy <lists@colorremedies.com>
Cc: <stable@vger.kernel.org> [3.1+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
According to Christopher Lameter two fixes have been merged for the same
problem. As far as I can tell, the code does not acquire the list_lock
and invoke kmalloc(). list_slab_objects() misses an unlock (the
counterpart to get_map()) and the memory allocated in free_partial()
isn't used.
Revert the mentioned commit.
Link: http://lkml.kernel.org/r/20200618201234.795692-1-bigeasy@linutronix.de
Fixes: aa456c7aeb ("slub: remove kmalloc under list_lock from list_slab_objects() V2")
Link: https://lkml.kernel.org/r/alpine.DEB.2.22.394.2006181501480.12014@www.lameter.com
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kzfree() function is normally used to clear some sensitive
information, like encryption keys, in the buffer before freeing it back to
the pool. Memset() is currently used for buffer clearing. However
unlikely, there is still a non-zero probability that the compiler may
choose to optimize away the memory clearing especially if LTO is being
used in the future.
To make sure that this optimization will never happen,
memzero_explicit(), which is introduced in v3.18, is now used in
kzfree() to future-proof it.
Link: http://lkml.kernel.org/r/20200616154311.12314-2-longman@redhat.com
Fixes: 3ef0e5ba46 ("slab: introduce kzfree()")
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Jason A . Donenfeld" <Jason@zx2c4.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It was found that running the LTP test on a PowerPC system could produce
erroneous values in /proc/meminfo, like:
MemTotal: 531915072 kB
MemFree: 507962176 kB
MemAvailable: 1100020596352 kB
Using bisection, the problem is tracked down to commit 9c315e4d7d ("mm:
memcg/slab: cache page number in memcg_(un)charge_slab()").
In memcg_uncharge_slab() with a "int order" argument:
unsigned int nr_pages = 1 << order;
:
mod_lruvec_state(lruvec, cache_vmstat_idx(s), -nr_pages);
The mod_lruvec_state() function will eventually call the
__mod_zone_page_state() which accepts a long argument. Depending on the
compiler and how inlining is done, "-nr_pages" may be treated as a
negative number or a very large positive number. Apparently, it was
treated as a large positive number in that PowerPC system leading to
incorrect stat counts. This problem hasn't been seen in x86-64 yet,
perhaps the gcc compiler there has some slight difference in behavior.
It is fixed by making nr_pages a signed value. For consistency, a similar
change is applied to memcg_charge_slab() as well.
Link: http://lkml.kernel.org/r/20200620184719.10994-1-longman@redhat.com
Fixes: 9c315e4d7d ("mm: memcg/slab: cache page number in memcg_(un)charge_slab()").
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh reports:
"While stressing compaction, one run oopsed on NULL capc->cc in
__free_one_page()'s task_capc(zone): compact_zone_order() had been
interrupted, and a page was being freed in the return from interrupt.
Though you would not expect it from the source, both gccs I was using
(4.8.1 and 7.5.0) had chosen to compile compact_zone_order() with the
".cc = &cc" implemented by mov %rbx,-0xb0(%rbp) immediately before
callq compact_zone - long after the "current->capture_control =
&capc". An interrupt in between those finds capc->cc NULL (zeroed by
an earlier rep stos).
This could presumably be fixed by a barrier() before setting
current->capture_control in compact_zone_order(); but would also need
more care on return from compact_zone(), in order not to risk leaking
a page captured by interrupt just before capture_control is reset.
Maybe that is the preferable fix, but I felt safer for task_capc() to
exclude the rather surprising possibility of capture at interrupt
time"
I have checked that gcc10 also behaves the same.
The advantage of fix in compact_zone_order() is that we don't add
another test in the page freeing hot path, and that it might prevent
future problems if we stop exposing pointers to uninitialized structures
in current task.
So this patch implements the suggestion for compact_zone_order() with
barrier() (and WRITE_ONCE() to prevent store tearing) for setting
current->capture_control, and prevents page leaking with
WRITE_ONCE/READ_ONCE in the proper order.
Link: http://lkml.kernel.org/r/20200616082649.27173-1-vbabka@suse.cz
Fixes: 5e1f0f098b ("mm, compaction: capture a page under direct compaction")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Hugh Dickins <hughd@google.com>
Suggested-by: Hugh Dickins <hughd@google.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Li Wang <liwang@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org> [5.1+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
do_swap_page() returns error codes from the VM_FAULT* space. try_charge()
might return -ENOMEM, though, and then do_swap_page() simply returns 0
which means a success.
We almost never return ENOMEM for GFP_KERNEL single page charge. Except
for async OOM handling (oom_disabled v1). So this needs translation to
VM_FAULT_OOM otherwise the the page fault path will not notify the
userspace and wait for an action.
Link: http://lkml.kernel.org/r/20200617090238.GL9499@dhcp22.suse.cz
Fixes: 4c6355b25e ("mm: memcontrol: charge swapin pages on instantiation")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the async page locking infrastructure, if IOCB_WAITQ is set in the
passed in iocb. The caller must expect an -EIOCBQUEUED return value,
which means that IO is started but not done yet. This is similar to how
O_DIRECT signals the same operation. Once the callback is received by
the caller for IO completion, the caller must retry the operation.
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Normally waiting for a page to become unlocked, or locking the page,
requires waiting for IO to complete. Add support for lock_page_async()
and wait_on_page_locked_async(), which are callback based instead. This
allows a caller to get notified when a page becomes unlocked, rather
than wait for it.
We add a new iocb field, ki_waitq, to pass in the necessary data for this
to happen. We can unionize this with ki_cookie, since that is only used
for polled IO. Polled IO can never co-exist with async callbacks, as it is
(by definition) polled completions. struct wait_page_key is made public,
and we define struct wait_page_async as the interface between the caller
and the core.
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
No functional changes in this patch, just in preparation for allowing
more callers.
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The read-ahead shouldn't block, so allow it to be done even if
IOCB_NOWAIT is set in the kiocb.
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
One fix for the interrupt rework we did last release which broke KVM-PR.
Three commits fixing some fallout from the READ_ONCE() changes interacting badly
with our 8xx 16K pages support, which uses a pte_t that is a structure of 4
actual PTEs.
A cleanup of the 8xx pte_update() to use the newly added pmd_off().
A fix for a crash when handling an oops if CONFIG_DEBUG_VIRTUAL is enabled.
A minor fix for the SPU syscall generation.
Thanks to:
Aneesh Kumar K.V, Christian Zigotzky, Christophe Leroy, Mike Rapoport,
Nicholas Piggin.
-----BEGIN PGP SIGNATURE-----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=qws5
-----END PGP SIGNATURE-----
Merge tag 'powerpc-5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
- One fix for the interrupt rework we did last release which broke
KVM-PR
- Three commits fixing some fallout from the READ_ONCE() changes
interacting badly with our 8xx 16K pages support, which uses a pte_t
that is a structure of 4 actual PTEs
- A cleanup of the 8xx pte_update() to use the newly added pmd_off()
- A fix for a crash when handling an oops if CONFIG_DEBUG_VIRTUAL is
enabled
- A minor fix for the SPU syscall generation
Thanks to Aneesh Kumar K.V, Christian Zigotzky, Christophe Leroy, Mike
Rapoport, Nicholas Piggin.
* tag 'powerpc-5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/8xx: Provide ptep_get() with 16k pages
mm: Allow arches to provide ptep_get()
mm/gup: Use huge_ptep_get() in gup_hugepte()
powerpc/syscalls: Use the number when building SPU syscall table
powerpc/8xx: use pmd_off() to access a PMD entry in pte_update()
powerpc/64s: Fix KVM interrupt using wrong save area
powerpc: Fix kernel crash in show_instructions() w/DEBUG_VIRTUAL
Since commit 9e343b467c ("READ_ONCE: Enforce atomicity for
{READ,WRITE}_ONCE() memory accesses") it is not possible anymore to
use READ_ONCE() to access complex page table entries like the one
defined for powerpc 8xx with 16k size pages.
Define a ptep_get() helper that architectures can override instead
of performing a READ_ONCE() on the page table entry pointer.
Fixes: 9e343b467c ("READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/087fa12b6e920e32315136b998aa834f99242695.1592225558.git.christophe.leroy@csgroup.eu
- fix build rules in binderfs sample
- fix build errors when Kbuild recurses to the top Makefile
- covert '---help---' in Kconfig to 'help'
-----BEGIN PGP SIGNATURE-----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=1NIT
-----END PGP SIGNATURE-----
Merge tag 'kbuild-v5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull more Kbuild updates from Masahiro Yamada:
- fix build rules in binderfs sample
- fix build errors when Kbuild recurses to the top Makefile
- covert '---help---' in Kconfig to 'help'
* tag 'kbuild-v5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
treewide: replace '---help---' in Kconfig files with 'help'
kbuild: fix broken builds because of GZIP,BZIP2,LZOP variables
samples: binderfs: really compile this sample and fix build issues
Since commit 84af7a6194 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.
This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.
There are a variety of indentation styles found.
a) 4 spaces + '---help---'
b) 7 spaces + '---help---'
c) 8 spaces + '---help---'
d) 1 space + 1 tab + '---help---'
e) 1 tab + '---help---' (correct indentation)
f) 1 tab + 1 space + '---help---'
g) 1 tab + 2 spaces + '---help---'
In order to convert all of them to 1 tab + 'help', I ran the
following commend:
$ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
KCSAN is a dynamic race detector, which relies on compile-time
instrumentation, and uses a watchpoint-based sampling approach to detect
races.
The feature was under development for quite some time and has already found
legitimate bugs.
Unfortunately it comes with a limitation, which was only understood late in
the development cycle:
It requires an up to date CLANG-11 compiler
CLANG-11 is not yet released (scheduled for June), but it's the only
compiler today which handles the kernel requirements and especially the
annotations of functions to exclude them from KCSAN instrumentation
correctly.
These annotations really need to work so that low level entry code and
especially int3 text poke handling can be completely isolated.
A detailed discussion of the requirements and compiler issues can be found
here:
https://lore.kernel.org/lkml/CANpmjNMTsY_8241bS7=XAfqvZHFLrVEkv_uM4aDUWE_kh3Rvbw@mail.gmail.com/
We came to the conclusion that trying to work around compiler limitations
and bugs again would end up in a major trainwreck, so requiring a working
compiler seemed to be the best choice.
For Continous Integration purposes the compiler restriction is manageable
and that's where most xxSAN reports come from.
For a change this limitation might make GCC people actually look at their
bugs. Some issues with CSAN in GCC are 7 years old and one has been 'fixed'
3 years ago with a half baken solution which 'solved' the reported issue
but not the underlying problem.
The KCSAN developers also ponder to use a GCC plugin to become independent,
but that's not something which will show up in a few days.
Blocking KCSAN until wide spread compiler support is available is not a
really good alternative because the continuous growth of lockless
optimizations in the kernel demands proper tooling support.
-----BEGIN PGP SIGNATURE-----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=iplm
-----END PGP SIGNATURE-----
Merge tag 'locking-kcsan-2020-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull the Kernel Concurrency Sanitizer from Thomas Gleixner:
"The Kernel Concurrency Sanitizer (KCSAN) is a dynamic race detector,
which relies on compile-time instrumentation, and uses a
watchpoint-based sampling approach to detect races.
The feature was under development for quite some time and has already
found legitimate bugs.
Unfortunately it comes with a limitation, which was only understood
late in the development cycle:
It requires an up to date CLANG-11 compiler
CLANG-11 is not yet released (scheduled for June), but it's the only
compiler today which handles the kernel requirements and especially
the annotations of functions to exclude them from KCSAN
instrumentation correctly.
These annotations really need to work so that low level entry code and
especially int3 text poke handling can be completely isolated.
A detailed discussion of the requirements and compiler issues can be
found here:
https://lore.kernel.org/lkml/CANpmjNMTsY_8241bS7=XAfqvZHFLrVEkv_uM4aDUWE_kh3Rvbw@mail.gmail.com/
We came to the conclusion that trying to work around compiler
limitations and bugs again would end up in a major trainwreck, so
requiring a working compiler seemed to be the best choice.
For Continous Integration purposes the compiler restriction is
manageable and that's where most xxSAN reports come from.
For a change this limitation might make GCC people actually look at
their bugs. Some issues with CSAN in GCC are 7 years old and one has
been 'fixed' 3 years ago with a half baken solution which 'solved' the
reported issue but not the underlying problem.
The KCSAN developers also ponder to use a GCC plugin to become
independent, but that's not something which will show up in a few
days.
Blocking KCSAN until wide spread compiler support is available is not
a really good alternative because the continuous growth of lockless
optimizations in the kernel demands proper tooling support"
* tag 'locking-kcsan-2020-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (76 commits)
compiler_types.h, kasan: Use __SANITIZE_ADDRESS__ instead of CONFIG_KASAN to decide inlining
compiler.h: Move function attributes to compiler_types.h
compiler.h: Avoid nested statement expression in data_race()
compiler.h: Remove data_race() and unnecessary checks from {READ,WRITE}_ONCE()
kcsan: Update Documentation to change supported compilers
kcsan: Remove 'noinline' from __no_kcsan_or_inline
kcsan: Pass option tsan-instrument-read-before-write to Clang
kcsan: Support distinguishing volatile accesses
kcsan: Restrict supported compilers
kcsan: Avoid inserting __tsan_func_entry/exit if possible
ubsan, kcsan: Don't combine sanitizer with kcov on clang
objtool, kcsan: Add kcsan_disable_current() and kcsan_enable_current_nowarn()
kcsan: Add __kcsan_{enable,disable}_current() variants
checkpatch: Warn about data_race() without comment
kcsan: Use GFP_ATOMIC under spin lock
Improve KCSAN documentation a bit
kcsan: Make reporting aware of KCSAN tests
kcsan: Fix function matching in report
kcsan: Change data_race() to no longer require marking racing accesses
kcsan: Move kcsan_{disable,enable}_current() to kcsan-checks.h
...
Action Required memory error should happen only when a processor is
about to access to a corrupted memory, so it's synchronous and only
affects current process/thread.
Recently commit 872e9a205c ("mm, memory_failure: don't send
BUS_MCEERR_AO for action required error") fixed the issue that Action
Required memory could unnecessarily send SIGBUS to the processes which
share the error memory. But we still have another issue that we could
send SIGBUS to a wrong thread.
This is because collect_procs() and task_early_kill() fails to add the
current process to "to-kill" list. So this patch is suggesting to fix
it. With this fix, SIGBUS(BUS_MCEERR_AR) is never sent to non-current
process/thread.
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Link: http://lkml.kernel.org/r/1591321039-22141-3-git-send-email-naoya.horiguchi@nec.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "hwpoison: fixes signaling on memory error"
This is a small patchset to solve issues in memory error handler to send
SIGBUS to proper process/thread as expected in configuration. Please
see descriptions in individual patches for more details.
This patch (of 2):
Early-kill policy is controlled from two types of settings, one is
per-process setting prctl(PR_MCE_KILL) and the other is system-wide
setting vm.memory_failure_early_kill. Users expect per-process setting
to override system-wide setting as many other settings do, but
early-kill setting doesn't work as such.
For example, if a system configures vm.memory_failure_early_kill to 1
(enabled), a process receives SIGBUS even if it's configured to
explicitly disable PF_MCE_KILL by prctl(). That's not desirable for
applications with their own policies.
This patch is suggesting to change the priority of these two types of
settings, by checking sysctl_memory_failure_early_kill only when a given
process has the default kill policy.
Note that this patch is solving a thread choice issue too.
Originally, collect_procs() always chooses the main thread when
vm.memory_failure_early_kill is 1, even if the process has a dedicated
thread for memory error handling. SIGBUS should be sent to the
dedicated thread if early-kill is enabled via
vm.memory_failure_early_kill as we are doing for PR_MCE_KILL_EARLY
processes.
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Link: http://lkml.kernel.org/r/1591321039-22141-1-git-send-email-naoya.horiguchi@nec.com
Link: http://lkml.kernel.org/r/1591321039-22141-2-git-send-email-naoya.horiguchi@nec.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge some more updates from Andrew Morton:
- various hotfixes and minor things
- hch's use_mm/unuse_mm clearnups
Subsystems affected by this patch series: mm/hugetlb, scripts, kcov,
lib, nilfs, checkpatch, lib, mm/debug, ocfs2, lib, misc.
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
kernel: set USER_DS in kthread_use_mm
kernel: better document the use_mm/unuse_mm API contract
kernel: move use_mm/unuse_mm to kthread.c
kernel: move use_mm/unuse_mm to kthread.c
stacktrace: cleanup inconsistent variable type
lib: test get_count_order/long in test_bitops.c
mm: add comments on pglist_data zones
ocfs2: fix spelling mistake and grammar
mm/debug_vm_pgtable: fix kernel crash by checking for THP support
lib: fix bitmap_parse() on 64-bit big endian archs
checkpatch: correct check for kernel parameters doc
nilfs2: fix null pointer dereference at nilfs_segctor_do_construct()
lib/lz4/lz4_decompress.c: document deliberate use of `&'
kcov: check kcov_softirq in kcov_remote_stop()
scripts/spelling: add a few more typos
khugepaged: selftests: fix timeout condition in wait_for_scan()
Merge the state of the locking kcsan branch before the read/write_once()
and the atomics modifications got merged.
Squash the fallout of the rebase on top of the read/write once and atomic
fallback work into the merge. The history of the original branch is
preserved in tag locking-kcsan-2020-06-02.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Switch the function documentation to kerneldoc comments, and add
WARN_ON_ONCE asserts that the calling thread is a kernel thread and does
not have ->mm set (or has ->mm set in the case of unuse_mm).
Also give the functions a kthread_ prefix to better document the use case.
[hch@lst.de: fix a comment typo, cover the newly merged use_mm/unuse_mm caller in vfio]
Link: http://lkml.kernel.org/r/20200416053158.586887-3-hch@lst.de
[sfr@canb.auug.org.au: powerpc/vas: fix up for {un}use_mm() rename]
Link: http://lkml.kernel.org/r/20200422163935.5aa93ba5@canb.auug.org.au
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [usb]
Acked-by: Haren Myneni <haren@linux.ibm.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Jason Wang <jasowang@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Link: http://lkml.kernel.org/r/20200404094101.672954-6-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "improve use_mm / unuse_mm", v2.
This series improves the use_mm / unuse_mm interface by better documenting
the assumptions, and my taking the set_fs manipulations spread over the
callers into the core API.
This patch (of 3):
Use the proper API instead.
Link: http://lkml.kernel.org/r/20200404094101.672954-1-hch@lst.de
These helpers are only for use with kernel threads, and I will tie them
more into the kthread infrastructure going forward. Also move the
prototypes to kthread.h - mmu_context.h was a little weird to start with
as it otherwise contains very low-level MM bits.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Jason Wang <jasowang@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: http://lkml.kernel.org/r/20200404094101.672954-1-hch@lst.de
Link: http://lkml.kernel.org/r/20200416053158.586887-1-hch@lst.de
Link: http://lkml.kernel.org/r/20200404094101.672954-5-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Architectures can have CONFIG_TRANSPARENT_HUGEPAGE enabled but no THP
support enabled based on platforms. For ex: with 4K PAGE_SIZE ppc64
supports THP only with radix translation.
This results in below crash when running with hash translation and 4K
PAGE_SIZE.
kernel BUG at arch/powerpc/include/asm/book3s/64/hash-4k.h:140!
cpu 0x61: Vector: 700 (Program Check) at [c000000ff948f860]
pc: debug_vm_pgtable+0x480/0x8b0
lr: debug_vm_pgtable+0x474/0x8b0
...
debug_vm_pgtable+0x374/0x8b0 (unreliable)
do_one_initcall+0x98/0x4f0
kernel_init_freeable+0x330/0x3fc
kernel_init+0x24/0x148
Check for THP support correctly
Link: http://lkml.kernel.org/r/20200608125252.407659-1-aneesh.kumar@linux.ibm.com
Fixes: 399145f9eb ("mm/debug: add tests validating architecture page table helpers")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
virtio-mem
doorbell mapping for vdpa
config interrupt support in ifc
fixes all over the place
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
-----BEGIN PGP SIGNATURE-----
iQFDBAABCAAtFiEEXQn9CHHI+FuUyooNKB8NuNKNVGkFAl7fZ6APHG1zdEByZWRo
YXQuY29tAAoJECgfDbjSjVRpkDoIAMcBcQx5su1iuX7vT35xzUWZO478eAf1jOMZ
7KxKUVBeztkcxVFUlRVRu9MR6wOzwHils+1HD6025775Smr5M6x3aJxR6xOORaBj
RoU6OVGkpDvbzsxlhW+xhONz4O7/RkveKJPCwzGjqHrsFeh92lkfTqroz/EuNpw+
LZsO0+DhdUf123HbwHQp5lxW8EjyrRabgeZZg/D9VLPhoCP88vCjRhBXU2GPuaUl
/UNXsQafn4xUgrxPaoN5f4Phn/P46NNrbZ1jmlkw/z/3QhF/DhktGXGaZsIHDCN/
vicUii0or5QLeBsZpMbKko/BIe2xWHxFjkMRhMOMZOfcBb6sMBI=
=auUa
-----END PGP SIGNATURE-----
Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio updates from Michael Tsirkin:
- virtio-mem: paravirtualized memory hotplug
- support doorbell mapping for vdpa
- config interrupt support in ifc
- fixes all over the place
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (40 commits)
vhost/test: fix up after API change
virtio_mem: convert device block size into 64bit
virtio-mem: drop unnecessary initialization
ifcvf: implement config interrupt in IFCVF
vhost: replace -1 with VHOST_FILE_UNBIND in ioctls
vhost_vdpa: Support config interrupt in vdpa
ifcvf: ignore continuous setting same status value
virtio-mem: Don't rely on implicit compiler padding for requests
virtio-mem: Try to unplug the complete online memory block first
virtio-mem: Use -ETXTBSY as error code if the device is busy
virtio-mem: Unplug subblocks right-to-left
virtio-mem: Drop manual check for already present memory
virtio-mem: Add parent resource for all added "System RAM"
virtio-mem: Better retry handling
virtio-mem: Offline and remove completely unplugged memory blocks
mm/memory_hotplug: Introduce offline_and_remove_memory()
virtio-mem: Allow to offline partially unplugged memory blocks
mm: Allow to offline unmovable PageOffline() pages via MEM_GOING_OFFLINE
virtio-mem: Paravirtualized memory hotunplug part 2
virtio-mem: Paravirtualized memory hotunplug part 1
...
Allow the callers to distinguish a real unmapped address vs a range
that can't be probed.
Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-24-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide alternative versions of probe_kernel_read, probe_kernel_write
and strncpy_from_kernel_unsafe that don't need set_fs magic, but instead
use arch hooks that are modelled after unsafe_{get,put}_user to access
kernel memory in an exception safe way.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-19-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Except for historical confusion in the kprobes/uprobes and bpf tracers,
which has been fixed now, there is no good reason to ever allow user
memory accesses from probe_kernel_read. Switch probe_kernel_read to only
read from kernel memory.
[akpm@linux-foundation.org: update it for "mm, dump_page(): do not crash with invalid mapping pointer"]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-17-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently architectures have to override every routine that probes
kernel memory, which includes a pure read and strcpy, both in strict
and not strict variants. Just provide a single arch hooks instead to
make sure all architectures cover all the cases.
[akpm@linux-foundation.org: fix !CONFIG_X86_64 build]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-11-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Each of the helpers has just two callers, which also different in
dealing with kernel or userspace pointers. Just open code the logic
in the callers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-10-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This matches the naming of strnlen_user, and also makes it more clear
what the function is supposed to do.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-9-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This matches the naming of strncpy_from_user_nofault, and also makes it
more clear what the function is supposed to do.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-8-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This matches the naming of strncpy_from_user, and also makes it more
clear what the function is supposed to do.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-7-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This file now also contains several helpers for accessing user memory.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-6-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add proper kerneldoc comments for probe_kernel_read_strict and
probe_kernel_read strncpy_from_unsafe_strict and explain the different
versus the non-strict version.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-5-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
maccess tends to define lots of underscore prefixed symbols that then
have other weak aliases. But except for two cases they are never
actually used, so remove them.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-3-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "clean up and streamline probe_kernel_* and friends", v4.
This series start cleaning up the safe kernel and user memory probing
helpers in mm/maccess.c, and then allows architectures to implement the
kernel probing without overriding the address space limit and temporarily
allowing access to user memory. It then switches x86 over to this new
mechanism by reusing the unsafe_* uaccess logic.
This version also switches to the saner copy_{from,to}_kernel_nofault
naming suggested by Linus.
I kept the x86 helpers as-is without calling unsage_{get,put}_user as that
avoids a number of hard to trace casts, and it will still work with the
asm-goto based version easily.
This patch (of 20):
probe_kernel_write() is not used by any modular code.
[sfr@canb.auug.org.au: turns out that probe_user_write is used in modular code]
Link: http://lkml.kernel.org/r/20200602195741.4faaa348@canb.auug.org.au
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-1-hch@lst.de
Link: http://lkml.kernel.org/r/20200521152301.2587579-2-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rename the mmap_sem field to mmap_lock. Any new uses of this lock should
now go through the new mmap locking api. The mmap_lock is still
implemented as a rwsem, though this could change in the future.
[akpm@linux-foundation.org: fix it for mm-gup-might_lock_readmmap_sem-in-get_user_pages_fast.patch]
Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-11-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add new APIs to assert that mmap_sem is held.
Using this instead of rwsem_is_locked and lockdep_assert_held[_write]
makes the assertions more tolerant of future changes to the lock type.
Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-10-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Define a new initializer for the mmap locking api. Initially this just
evaluates to __RWSEM_INITIALIZER as the API is defined as wrappers around
rwsem.
Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-9-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The replacement of <asm/pgrable.h> with <linux/pgtable.h> made the include
of the latter in the middle of asm includes. Fix this up with the aid of
the below script and manual adjustments here and there.
import sys
import re
if len(sys.argv) is not 3:
print "USAGE: %s <file> <header>" % (sys.argv[0])
sys.exit(1)
hdr_to_move="#include <linux/%s>" % sys.argv[2]
moved = False
in_hdrs = False
with open(sys.argv[1], "r") as f:
lines = f.readlines()
for _line in lines:
line = _line.rstrip('
')
if line == hdr_to_move:
continue
if line.startswith("#include <linux/"):
in_hdrs = True
elif not moved and in_hdrs:
moved = True
print hdr_to_move
print line
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-4-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The include/linux/pgtable.h is going to be the home of generic page table
manipulation functions.
Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and
make the latter include asm/pgtable.h.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-3-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: consolidate definitions of page table accessors", v2.
The low level page table accessors (pXY_index(), pXY_offset()) are
duplicated across all architectures and sometimes more than once. For
instance, we have 31 definition of pgd_offset() for 25 supported
architectures.
Most of these definitions are actually identical and typically it boils
down to, e.g.
static inline unsigned long pmd_index(unsigned long address)
{
return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
}
static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
{
return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
}
These definitions can be shared among 90% of the arches provided
XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined.
For architectures that really need a custom version there is always
possibility to override the generic version with the usual ifdefs magic.
These patches introduce include/linux/pgtable.h that replaces
include/asm-generic/pgtable.h and add the definitions of the page table
accessors to the new header.
This patch (of 12):
The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the
functions involving page table manipulations, e.g. pte_alloc() and
pmd_alloc(). So, there is no point to explicitly include <asm/pgtable.h>
in the files that include <linux/mm.h>.
The include statements in such cases are remove with a simple loop:
for f in $(git grep -l "include <linux/mm.h>") ; do
sed -i -e '/include <asm\/pgtable.h>/ d' $f
done
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge still more updates from Andrew Morton:
"Various trees. Mainly those parts of MM whose linux-next dependents
are now merged. I'm still sitting on ~160 patches which await merges
from -next.
Subsystems affected by this patch series: mm/proc, ipc, dynamic-debug,
panic, lib, sysctl, mm/gup, mm/pagemap"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (52 commits)
doc: cgroup: update note about conditions when oom killer is invoked
module: move the set_fs hack for flush_icache_range to m68k
nommu: use flush_icache_user_range in brk and mmap
binfmt_flat: use flush_icache_user_range
exec: use flush_icache_user_range in read_code
exec: only build read_code when needed
m68k: implement flush_icache_user_range
arm: rename flush_cache_user_range to flush_icache_user_range
xtensa: implement flush_icache_user_range
sh: implement flush_icache_user_range
asm-generic: add a flush_icache_user_range stub
mm: rename flush_icache_user_range to flush_icache_user_page
arm,sparc,unicore32: remove flush_icache_user_range
riscv: use asm-generic/cacheflush.h
powerpc: use asm-generic/cacheflush.h
openrisc: use asm-generic/cacheflush.h
m68knommu: use asm-generic/cacheflush.h
microblaze: use asm-generic/cacheflush.h
ia64: use asm-generic/cacheflush.h
hexagon: use asm-generic/cacheflush.h
...
All of the pin_user_pages*() API calls will cause pages to be
dma-pinned. As such, they are all suitable for either DMA, RDMA, and/or
Direct IO.
The documentation should say so, but it was instead saying that three of
the API calls were only suitable for Direct IO. This was discovered
when a reviewer wondered why an API call that specifically recommended
against Case 2 (DMA/RDMA) was being used in a DMA situation [1].
Fix this by simply deleting those claims. The gup.c comments already
refer to the more extensive Documentation/core-api/pin_user_pages.rst,
which does have the correct guidance. So let's just write it once,
there.
[1] https://lore.kernel.org/r/20200529074658.GM30374@kadam
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Acked-by: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/20200529084515.46259-1-jhubbard@nvidia.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This code was using get_user_pages*(), and all of the callers so far
were in a "Case 2" scenario (DMA/RDMA), using the categorization from [1].
That means that it's time to convert the get_user_pages*() + put_page()
calls to pin_user_pages*() + unpin_user_pages() calls.
There is some helpful background in [2]: basically, this is a small part
of fixing a long-standing disconnect between pinning pages, and file
systems' use of those pages.
[1] Documentation/core-api/pin_user_pages.rst
[2] "Explicit pinning of user-space pages":
https://lwn.net/Articles/807108/
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Link: http://lkml.kernel.org/r/20200527223243.884385-3-jhubbard@nvidia.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm/gup: introduce pin_user_pages_locked(), use it in frame_vector.c", v2.
This adds yet one more pin_user_pages*() variant, and uses that to
convert mm/frame_vector.c.
With this, along with maybe 20 or 30 other recent patches in various
trees, we are close to having the relevant gup call sites
converted--with the notable exception of the bio/block layer.
This patch (of 2):
Introduce pin_user_pages_locked(), which is nearly identical to
get_user_pages_locked() except that it sets FOLL_PIN and rejects
FOLL_GET.
As with other pairs of get_user_pages*() and pin_user_pages() API calls,
it's prudent to assert that FOLL_PIN is *not* set in the
get_user_pages*() call, so add that as part of this.
[jhubbard@nvidia.com: v2]
Link: http://lkml.kernel.org/r/20200531234131.770697-2-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Link: http://lkml.kernel.org/r/20200531234131.770697-1-jhubbard@nvidia.com
Link: http://lkml.kernel.org/r/20200527223243.884385-1-jhubbard@nvidia.com
Link: http://lkml.kernel.org/r/20200527223243.884385-2-jhubbard@nvidia.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
API __get_user_pages_fast() renamed to get_user_pages_fast_only() to
align with pin_user_pages_fast_only().
As part of this we will get rid of write parameter. Instead caller will
pass FOLL_WRITE to get_user_pages_fast_only(). This will not change any
existing functionality of the API.
All the callers are changed to pass FOLL_WRITE.
Also introduce get_user_page_fast_only(), and use it in a few places
that hard-code nr_pages to 1.
Updated the documentation of the API.
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Paul Mackerras <paulus@ozlabs.org> [arch/powerpc/kvm]
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Michal Suchanek <msuchanek@suse.de>
Link: http://lkml.kernel.org/r/1590396812-31277-1-git-send-email-jrdr.linux@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We can now handle sysctl parameters on kernel command line, but
historically some parameters introduced their own command line
equivalent, which we don't want to remove for compatibility reasons.
We can, however, convert them to the generic infrastructure with a table
translating the legacy command line parameters to their sysctl names,
and removing the one-off param handlers.
This patch adds the support and makes the first conversion to
demonstrate it, on the (deprecated) numa_zonelist_order parameter.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Guilherme G . Piccoli" <gpiccoli@canonical.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Ivan Teterevkov <ivan.teterevkov@nutanix.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200427180433.7029-3-vbabka@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
'Idle page tracking' users can pass random pfn that might be mapped to an
offline page. To avoid accessing such pages, this commit modifies the
'page_idle_get_page()' to use 'pfn_to_online_page()' instead of
'pfn_valid()' and 'pfn_to_page()' combination, so that the pfn mapped to
an offline page can be skipped.
Reported-by: David Hildenbrand <david@redhat.com>
Signed-off-by: SeongJae Park <sjpark@amazon.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Link: http://lkml.kernel.org/r/20200605092502.18018-2-sjpark@amazon.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull sparc updates from David Miller:
- Rework the sparc32 page tables so that READ_ONCE(*pmd), as done by
generic code, operates on a word sized element. From Will Deacon.
- Some scnprintf() conversions, from Chen Zhou.
- A pin_user_pages() conversion from John Hubbard.
- Several 32-bit ptrace register handling fixes and such from Al Viro.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next:
fix a braino in "sparc32: fix register window handling in genregs32_[gs]et()"
sparc32: mm: Only call ctor()/dtor() functions for first and last user
sparc32: mm: Disable SPLIT_PTLOCK_CPUS
sparc32: mm: Don't try to free page-table pages if ctor() fails
sparc32: register memory occupied by kernel as memblock.memory
sparc: remove unused header file nfs_fs.h
sparc32: fix register window handling in genregs32_[gs]et()
sparc64: fix misuses of access_process_vm() in genregs32_[sg]et()
oradax: convert get_user_pages() --> pin_user_pages()
sparc: use scnprintf() in show_pciobppath_attr() in vio.c
sparc: use scnprintf() in show_pciobppath_attr() in pci.c
tty: vcc: Fix error return code in vcc_probe()
sparc32: mm: Reduce allocation size for PMD and PTE tables
sparc32: mm: Change pgtable_t type to pte_t * instead of struct page *
sparc32: mm: Restructure sparc32 MMU page-table layout
sparc32: mm: Fix argument checking in __srmmu_get_nocache()
sparc64: Replace zero-length array with flexible-array
sparc: mm: return true,false in kern_addr_valid()
- Support for userspace to send requests directly to the on-chip GZIP
accelerator on Power9.
- Rework of our lockless page table walking (__find_linux_pte()) to make it
safe against parallel page table manipulations without relying on an IPI for
serialisation.
- A series of fixes & enhancements to make our machine check handling more
robust.
- Lots of plumbing to add support for "prefixed" (64-bit) instructions on
Power10.
- Support for using huge pages for the linear mapping on 8xx (32-bit).
- Remove obsolete Xilinx PPC405/PPC440 support, and an associated sound driver.
- Removal of some obsolete 40x platforms and associated cruft.
- Initial support for booting on Power10.
- Lots of other small features, cleanups & fixes.
Thanks to:
Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan, Andrey Abramov,
Aneesh Kumar K.V, Balamuruhan S, Bharata B Rao, Bulent Abali, Cédric Le
Goater, Chen Zhou, Christian Zigotzky, Christophe JAILLET, Christophe Leroy,
Dmitry Torokhov, Emmanuel Nicolet, Erhard F., Gautham R. Shenoy, Geoff Levand,
George Spelvin, Greg Kurz, Gustavo A. R. Silva, Gustavo Walbon, Haren Myneni,
Hari Bathini, Joel Stanley, Jordan Niethe, Kajol Jain, Kees Cook, Leonardo
Bras, Madhavan Srinivasan., Mahesh Salgaonkar, Markus Elfring, Michael
Neuling, Michal Simek, Nathan Chancellor, Nathan Lynch, Naveen N. Rao,
Nicholas Piggin, Oliver O'Halloran, Paul Mackerras, Pingfan Liu, Qian Cai, Ram
Pai, Raphael Moreira Zinsly, Ravi Bangoria, Sam Bobroff, Sandipan Das, Segher
Boessenkool, Stephen Rothwell, Sukadev Bhattiprolu, Tyrel Datwyler, Wolfram
Sang, Xiongfeng Wang.
-----BEGIN PGP SIGNATURE-----
iQJHBAABCAAxFiEEJFGtCPCthwEv2Y/bUevqPMjhpYAFAl7aYZ8THG1wZUBlbGxl
cm1hbi5pZC5hdQAKCRBR6+o8yOGlgPiKD/9zNCuZLFMAFrIdbm0HlYA2RGYZFT75
GUHsqYyei1pxA7PgM3KwJiXELVODsBv0eQbgNh1tbecKrxPRegN/cywd1KLjPZ7I
v5/qweQP8MvR0RhzjbhvUcO0jq/f8u2LbJr5mUfVzjU6tAvrvcWo3oZqDElsekCS
kgyOH3r1vZ2PLTMiGFhb0gWi2iqc+6BHU1AFCGPCMjB1Vu5d5+54VvZ/6lllGsOF
yg9CBXmmVvQ+Bn6tH4zdEB78FYxnAIwBqlbmL79i5ca+HQJ0Sw6HuPRy9XYq35p6
2EiXS4Wrgp7i7+1TN3HO362u5Onb8TSyQU7NS6yCFPoJ6JQxcJMBIw6mHhnXOPuZ
CrjgcdwUMjx8uDoKmX1Epbfuex2w+AysW+4yBHPFiSgl3klKC3D0wi95mR485w2F
rN8uzJtrDeFKcYZJG7IoB/cgFCCPKGf9HaXr8q0S/jBKMffx91ul3cfzlfdIXOCw
FDNw/+ZX7UD6ddFEG12ZTO+vdL8yf1uCRT/DIZwUiDMIA0+M6F4nc7j3lfyZfoO1
65f9UlhoLxScq7VH2fKH4UtZatO9cPID2z1CmiY4UbUIPtFDepSuYClgLF+Duf4b
rkfxhKU0+Ja1zNH5XNc+L+Bc5/W4lFiJXz02dYIjtHoUpWkc1aToOETVwzggYFNM
G3PXIBOI0jRgRw==
=o0WU
-----END PGP SIGNATURE-----
Merge tag 'powerpc-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
- Support for userspace to send requests directly to the on-chip GZIP
accelerator on Power9.
- Rework of our lockless page table walking (__find_linux_pte()) to
make it safe against parallel page table manipulations without
relying on an IPI for serialisation.
- A series of fixes & enhancements to make our machine check handling
more robust.
- Lots of plumbing to add support for "prefixed" (64-bit) instructions
on Power10.
- Support for using huge pages for the linear mapping on 8xx (32-bit).
- Remove obsolete Xilinx PPC405/PPC440 support, and an associated sound
driver.
- Removal of some obsolete 40x platforms and associated cruft.
- Initial support for booting on Power10.
- Lots of other small features, cleanups & fixes.
Thanks to: Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan,
Andrey Abramov, Aneesh Kumar K.V, Balamuruhan S, Bharata B Rao, Bulent
Abali, Cédric Le Goater, Chen Zhou, Christian Zigotzky, Christophe
JAILLET, Christophe Leroy, Dmitry Torokhov, Emmanuel Nicolet, Erhard F.,
Gautham R. Shenoy, Geoff Levand, George Spelvin, Greg Kurz, Gustavo A.
R. Silva, Gustavo Walbon, Haren Myneni, Hari Bathini, Joel Stanley,
Jordan Niethe, Kajol Jain, Kees Cook, Leonardo Bras, Madhavan
Srinivasan., Mahesh Salgaonkar, Markus Elfring, Michael Neuling, Michal
Simek, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin,
Oliver O'Halloran, Paul Mackerras, Pingfan Liu, Qian Cai, Ram Pai,
Raphael Moreira Zinsly, Ravi Bangoria, Sam Bobroff, Sandipan Das, Segher
Boessenkool, Stephen Rothwell, Sukadev Bhattiprolu, Tyrel Datwyler,
Wolfram Sang, Xiongfeng Wang.
* tag 'powerpc-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (299 commits)
powerpc/pseries: Make vio and ibmebus initcalls pseries specific
cxl: Remove dead Kconfig options
powerpc: Add POWER10 architected mode
powerpc/dt_cpu_ftrs: Add MMA feature
powerpc/dt_cpu_ftrs: Enable Prefixed Instructions
powerpc/dt_cpu_ftrs: Advertise support for ISA v3.1 if selected
powerpc: Add support for ISA v3.1
powerpc: Add new HWCAP bits
powerpc/64s: Don't set FSCR bits in INIT_THREAD
powerpc/64s: Save FSCR to init_task.thread.fscr after feature init
powerpc/64s: Don't let DT CPU features set FSCR_DSCR
powerpc/64s: Don't init FSCR_DSCR in __init_FSCR()
powerpc/32s: Fix another build failure with CONFIG_PPC_KUAP_DEBUG
powerpc/module_64: Use special stub for _mcount() with -mprofile-kernel
powerpc/module_64: Simplify check for -mprofile-kernel ftrace relocations
powerpc/module_64: Consolidate ftrace code
powerpc/32: Disable KASAN with pages bigger than 16k
powerpc/uaccess: Don't set KUEP by default on book3s/32
powerpc/uaccess: Don't set KUAP by default on book3s/32
powerpc/8xx: Reduce time spent in allow_user_access() and friends
...
Merge yet more updates from Andrew Morton:
- More MM work. 100ish more to go. Mike Rapoport's "mm: remove
__ARCH_HAS_5LEVEL_HACK" series should fix the current ppc issue
- Various other little subsystems
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (127 commits)
lib/ubsan.c: fix gcc-10 warnings
tools/testing/selftests/vm: remove duplicate headers
selftests: vm: pkeys: fix multilib builds for x86
selftests: vm: pkeys: use the correct page size on powerpc
selftests/vm/pkeys: override access right definitions on powerpc
selftests/vm/pkeys: test correct behaviour of pkey-0
selftests/vm/pkeys: introduce a sub-page allocator
selftests/vm/pkeys: detect write violation on a mapped access-denied-key page
selftests/vm/pkeys: associate key on a mapped page and detect write violation
selftests/vm/pkeys: associate key on a mapped page and detect access violation
selftests/vm/pkeys: improve checks to determine pkey support
selftests/vm/pkeys: fix assertion in test_pkey_alloc_exhaust()
selftests/vm/pkeys: fix number of reserved powerpc pkeys
selftests/vm/pkeys: introduce powerpc support
selftests/vm/pkeys: introduce generic pkey abstractions
selftests: vm: pkeys: use the correct huge page size
selftests/vm/pkeys: fix alloc_random_pkey() to make it really random
selftests/vm/pkeys: fix assertion in pkey_disable_set/clear()
selftests/vm/pkeys: fix pkey_disable_clear()
selftests: vm: pkeys: add helpers for pkey bits
...
Fixes coccicheck warnings:
mm/zbud.c:246:1-20: WARNING: Assignment of 0/1 to bool variable
mm/mremap.c:777:2-8: WARNING: Assignment of 0/1 to bool variable
mm/huge_memory.c:525:9-10: WARNING: return of 0/1 in function 'is_transparent_hugepage' with return type bool
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1586835930-47076-1-git-send-email-zou_wei@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a comment in typo, fix it.
Signed-off-by: Ethon Paul <ethp@qq.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200411004043.14686-1-ethp@qq.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a typo in comment, fix it.
Signed-off-by: Ethon Paul <ethp@qq.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200411003513.14613-1-ethp@qq.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a typo in comment, fix it.
Signed-off-by: Ethon Paul <ethp@qq.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200411002955.14545-1-ethp@qq.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a typo in comment, fix it.
Signed-off-by: Ethon Paul <ethp@qq.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/20200411002247.14468-1-ethp@qq.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a typo in comment, fix it.
Signed-off-by: Ethon Paul <ethp@qq.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Link: http://lkml.kernel.org/r/20200411064723.15855-1-ethp@qq.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are some typos in comment, fix them.
s/responsiblity/responsibility
s/oflline/offline
Signed-off-by: Ethon Paul <ethp@qq.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200411064246.15781-1-ethp@qq.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are some typos in comment, fix them.
s/Fortunatly/Fortunately
s/taked/taken
s/necessory/necessary
s/shink/shrink
Signed-off-by: Ethon Paul <ethp@qq.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200411064009.15727-1-ethp@qq.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a typo in comment, fix it.
Signed-off-by: Ethon Paul <ethp@qq.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Link: http://lkml.kernel.org/r/20200411065141.15936-1-ethp@qq.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a typo in comment, fix it.
Signed-off-by: Ethon Paul <ethp@qq.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Link: http://lkml.kernel.org/r/20200411071041.16161-1-ethp@qq.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a typo in commet, fix it.
Signed-off-by: Ethon Paul <ethp@qq.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Link: http://lkml.kernel.org/r/20200411070701.16097-1-ethp@qq.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a typo in comment, fix it.
Signed-off-by: Ethon Paul <ethp@qq.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Link: http://lkml.kernel.org/r/20200411070307.16021-1-ethp@qq.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are some typos, fix them.
s/regsitration/registration
s/santity/sanity
s/decremeting/decrementing
Signed-off-by: Ethon Paul <ethp@qq.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Link: http://lkml.kernel.org/r/20200411071544.16222-1-ethp@qq.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a typo in comment, fix it.
Signed-off-by: Ethon Paul <ethp@qq.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Link: http://lkml.kernel.org/r/20200410163206.14016-1-ethp@qq.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a typo in comment, fix it.
Signed-off-by: Ethon Paul <ethp@qq.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Link: http://lkml.kernel.org/r/20200410162427.13927-1-ethp@qq.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a typo in comment, fix it.
s/recoreded/recorded
Signed-off-by: Ethon Paul <ethp@qq.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Link: http://lkml.kernel.org/r/20200410160328.13843-1-ethp@qq.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Memory hotlug is broken for 32b systems at least since c6f03e2903 ("mm,
memory_hotplug: remove zone restrictions") which has considerably reworked
how can be memory associated with movable/kernel zones. The same is not
really trivial to achieve in 32b where only lowmem is the kernel zone.
While we can tweak this immediate problem around there are likely other
land mines hidden at other places.
It is also quite dubious that there is a real usecase for the memory
hotplug on 32b in the first place. Low memory is just too small to be
hotplugable (for hot add) and generally unusable for hotremove. Adding
more memory to highmem is also dubious because it would increase the low
mem or vmalloc space pressure for memmaps.
Restrict the functionality to 64b systems. This will help future
development to focus on usecases that have real life application. We can
remove this restriction in future in presence of a real life usecase of
course but until then make it explicit that hotplug on 32b is broken and
requires a non trivial amount of work to fix.
Robin said:
"32-bit Arm doesn't support memory hotplug, and as far as I'm aware
there's little likelihood of it ever wanting to. FWIW it looks like
SuperH is the only pure-32-bit architecture to have hotplug support at
all"
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>
Link: http://lkml.kernel.org/r/20200218100532.GA4151@dhcp22.suse.cz
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206401
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm/memory_hotplug: Interface to add driver-managed system
ram", v4.
kexec (via kexec_load()) can currently not properly handle memory added
via dax/kmem, and will have similar issues with virtio-mem. kexec-tools
will currently add all memory to the fixed-up initial firmware memmap. In
case of dax/kmem, this means that - in contrast to a proper reboot - how
that persistent memory will be used can no longer be configured by the
kexec'd kernel. In case of virtio-mem it will be harmful, because that
memory might contain inaccessible pieces that require coordination with
hypervisor first.
In both cases, we want to let the driver in the kexec'd kernel handle
detecting and adding the memory, like during an ordinary reboot.
Introduce add_memory_driver_managed(). More on the samentics are in patch
#1.
In the future, we might want to make this behavior configurable for
dax/kmem- either by configuring it in the kernel (which would then also
allow to configure kexec_file_load()) or in kexec-tools by also adding
"System RAM (kmem)" memory from /proc/iomem to the fixed-up initial
firmware memmap.
More on the motivation can be found in [1] and [2].
[1] https://lkml.kernel.org/r/20200429160803.109056-1-david@redhat.com
[2] https://lkml.kernel.org/r/20200430102908.10107-1-david@redhat.com
This patch (of 3):
Some device drivers rely on memory they managed to not get added to the
initial (firmware) memmap as system RAM - so it's not used as initial
system RAM by the kernel and the driver is under control. While this is
the case during cold boot and after a reboot, kexec is not aware of that
and might add such memory to the initial (firmware) memmap of the kexec
kernel. We need ways to teach kernel and userspace that this system ram
is different.
For example, dax/kmem allows to decide at runtime if persistent memory is
to be used as system ram. Another future user is virtio-mem, which has to
coordinate with its hypervisor to deal with inaccessible parts within
memory resources.
We want to let users in the kernel (esp. kexec) but also user space
(esp. kexec-tools) know that this memory has different semantics and
needs to be handled differently:
1. Don't create entries in /sys/firmware/memmap/
2. Name the memory resource "System RAM ($DRIVER)" (exposed via
/proc/iomem) ($DRIVER might be "kmem", "virtio_mem").
3. Flag the memory resource IORESOURCE_MEM_DRIVER_MANAGED
/sys/firmware/memmap/ [1] represents the "raw firmware-provided memory
map" because "on most architectures that firmware-provided memory map is
modified afterwards by the kernel itself". The primary user is kexec on
x86-64. Since commit d96ae53091 ("memory-hotplug: create
/sys/firmware/memmap entry for new memory"), we add all hotplugged memory
to that firmware memmap - which makes perfect sense for traditional memory
hotplug on x86-64, where real HW will also add hotplugged DIMMs to the
firmware memmap. We replicate what the "raw firmware-provided memory map"
looks like after hot(un)plug.
To keep things simple, let the user provide the full resource name instead
of only the driver name - this way, we don't have to manually
allocate/craft strings for memory resources. Also use the resource name
to make decisions, to avoid passing additional flags. In case the name
isn't "System RAM", it's special.
We don't have to worry about firmware_map_remove() on the removal path.
If there is no entry, it will simply return with -EINVAL.
We'll adapt dax/kmem in a follow-up patch.
[1] https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-firmware-memmap
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Link: http://lkml.kernel.org/r/20200508084217.9160-1-david@redhat.com
Link: http://lkml.kernel.org/r/20200508084217.9160-3-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The comment in add_memory_resource() is stale: hotadd_new_pgdat() will no
longer call get_pfn_range_for_nid(), as a hotadded pgdat will simply span
no pages at all, until memory is moved to the zone/node via
move_pfn_range_to_zone() - e.g., when onlining memory blocks.
The only archs that care about memblocks for hotplugged memory (either for
iterating over all system RAM or testing for memory validity) are arm64,
s390x, and powerpc - due to CONFIG_ARCH_KEEP_MEMBLOCK. Without
CONFIG_ARCH_KEEP_MEMBLOCK, we can simply stop messing with memblocks.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Link: http://lkml.kernel.org/r/20200422155353.25381-3-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm/memory_hotplug: handle memblocks only with
CONFIG_ARCH_KEEP_MEMBLOCK", v1.
A hotadded node/pgdat will span no pages at all, until memory is moved to
the zone/node via move_pfn_range_to_zone() -> resize_pgdat_range - e.g.,
when onlining memory blocks. We don't have to initialize the
node_start_pfn to the memory we are adding.
This patch (of 2):
Especially, there is an inconsistency:
- Hotplugging memory to a memory-less node with cpus: node_start_pf == 0
- Offlining and removing last memory from a node: node_start_pfn == 0
- Hotplugging memory to a memory-less node without cpus: node_start_pfn != 0
As soon as memory is onlined, node_start_pfn is overwritten with the
actual start. E.g., when adding two DIMMs but only onlining one of both,
only that DIMM (with online memory blocks) is spanned by the node.
Currently, the validity of node_start_pfn really is linked to
node_spanned_pages != 0. With node_spanned_pages == 0 (e.g., before
onlining memory), it has no meaning.
So let's stop setting node_start_pfn, just to be overwritten via
move_pfn_range_to_zone(). This avoids confusion when looking at the code,
wondering which magic will be performed with the node_start_pfn in this
function, when hotadding a pgdat.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Michal Hocko <mhocko@suse.com>
Link: http://lkml.kernel.org/r/20200422155353.25381-1-david@redhat.com
Link: http://lkml.kernel.org/r/20200422155353.25381-2-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fortunately, all users of is_mem_section_removable() are gone. Get rid of
it, including some now unnecessary functions.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Oscar Salvador <osalvador@suse.de>
Link: http://lkml.kernel.org/r/20200407135416.24093-3-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For kvmalloc'ed data object that contains sensitive information like
cryptographic keys, we need to make sure that the buffer is always cleared
before freeing it. Using memset() alone for buffer clearing may not
provide certainty as the compiler may compile it away. To be sure, the
special memzero_explicit() has to be used.
This patch introduces a new kvfree_sensitive() for freeing those sensitive
data objects allocated by kvmalloc(). The relevant places where
kvfree_sensitive() can be used are modified to use it.
Fixes: 4f0882491a ("KEYS: Avoid false positive ENOMEM error on key read")
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Link: http://lkml.kernel.org/r/20200407200318.11711-1-longman@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a typo in comment, fix it.
"nother" -> "another"
Signed-off-by: Jeongtae Park <jtp.park@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20200604185239.20765-1-jtp.park@samsung.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds tests which will validate architecture page table helpers and
other accessors in their compliance with expected generic MM semantics.
This will help various architectures in validating changes to existing
page table helpers or addition of new ones.
This test covers basic page table entry transformations including but not
limited to old, young, dirty, clean, write, write protect etc at various
level along with populating intermediate entries with next page table page
and validating them.
Test page table pages are allocated from system memory with required size
and alignments. The mapped pfns at page table levels are derived from a
real pfn representing a valid kernel text symbol. This test gets called
via late_initcall().
This test gets built and run when CONFIG_DEBUG_VM_PGTABLE is selected.
Any architecture, which is willing to subscribe this test will need to
select ARCH_HAS_DEBUG_VM_PGTABLE. For now this is limited to arc, arm64,
x86, s390 and powerpc platforms where the test is known to build and run
successfully Going forward, other architectures too can subscribe the test
after fixing any build or runtime problems with their page table helpers.
Folks interested in making sure that a given platform's page table helpers
conform to expected generic MM semantics should enable the above config
which will just trigger this test during boot. Any non conformity here
will be reported as an warning which would need to be fixed. This test
will help catch any changes to the agreed upon semantics expected from
generic MM and enable platforms to accommodate it thereafter.
[anshuman.khandual@arm.com: v17]
Link: http://lkml.kernel.org/r/1587436495-22033-3-git-send-email-anshuman.khandual@arm.com
[anshuman.khandual@arm.com: v18]
Link: http://lkml.kernel.org/r/1588564865-31160-3-git-send-email-anshuman.khandual@arm.com
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [s390]
Tested-by: Christophe Leroy <christophe.leroy@c-s.fr> [ppc32]
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Link: http://lkml.kernel.org/r/1583919272-24178-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are no architectures that use include/asm-generic/5level-fixup.h
therefore it can be removed along with __ARCH_HAS_5LEVEL_HACK define and
the code it surrounds
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: James Morse <james.morse@arm.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200414153455.21744-15-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This check was added by commit 82f71ae4a2 ("mm: catch memory
commitment underflow") in 2014 to have a safety check for issues which
have been fixed. And there has been few report caught by it, as
described in its commit log:
: This shouldn't happen any more - the previous two patches fixed
: the committed_as underflow issues.
But it was really found by Qian Cai when he used the LTP memory stress
suite to test a RFC patchset, which tries to improve scalability of
per-cpu counter 'vm_committed_as', by chosing a bigger 'batch' number for
loose overcommit policies (OVERCOMMIT_ALWAYS and OVERCOMMIT_GUESS), while
keeping current number for OVERCOMMIT_NEVER.
With that patchset, when system firstly uses a loose policy, the
'vm_committed_as' count could be a big negative value, as its big 'batch'
number allows a big deviation, then when the policy is changed to
OVERCOMMIT_NEVER, the 'batch' will be decreased to a much smaller value,
thus hits this WARN check.
To mitigate this, one proposed solution is to queue work on all online
CPUs to do a local sync for 'vm_committed_as' when changing policy to
OVERCOMMIT_NEVER, plus some global syncing to garante the case won't be
hit.
But this solution is costy and slow, given this check hasn't shown real
trouble or benefit, simply drop it from one hot path of MM. And perf
stats does show some tiny saving for removing it.
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Qian Cai <cai@lca.pw>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/20200603094804.GB89848@shbuild999.sh.intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The original code in mm/mremap.c checks huge pmd by:
if (is_swap_pmd(*old_pmd) || pmd_trans_huge(*old_pmd)) {
However, a DAX mapped nvdimm is mapped as huge page (by default) but it
is not transparent huge page (_PAGE_PSE | PAGE_DEVMAP). This commit
changes the condition to include the case.
This addresses CVE-2020-10757.
Fixes: 5c7fb56e5e ("mm, dax: dax-pmd vs thp-pmd vs hugetlbfs-pmd")
Cc: <stable@vger.kernel.org>
Reported-by: Fan Yang <Fan_Yang@sjtu.edu.cn>
Signed-off-by: Fan Yang <Fan_Yang@sjtu.edu.cn>
Tested-by: Fan Yang <Fan_Yang@sjtu.edu.cn>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
virtio-mem wants to offline and remove a memory block once it unplugged
all subblocks (e.g., using alloc_contig_range()). Let's provide
an interface to do that from a driver. virtio-mem already supports to
offline partially unplugged memory blocks. Offlining a fully unplugged
memory block will not require to migrate any pages. All unplugged
subblocks are PageOffline() and have a reference count of 0 - so
offlining code will simply skip them.
All we need is an interface to offline and remove the memory from kernel
module context, where we don't have access to the memory block devices
(esp. find_memory_block() and device_offline()) and the device hotplug
lock.
To keep things simple, allow to only work on a single memory block.
Acked-by: Michal Hocko <mhocko@suse.com>
Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20200507140139.17083-9-david@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
virtio-mem wants to allow to offline memory blocks of which some parts
were unplugged (allocated via alloc_contig_range()), especially, to later
offline and remove completely unplugged memory blocks. The important part
is that PageOffline() has to remain set until the section is offline, so
these pages will never get accessed (e.g., when dumping). The pages should
not be handed back to the buddy (which would require clearing PageOffline()
and result in issues if offlining fails and the pages are suddenly in the
buddy).
Let's allow to do that by allowing to isolate any PageOffline() page
when offlining. This way, we can reach the memory hotplug notifier
MEM_GOING_OFFLINE, where the driver can signal that he is fine with
offlining this page by dropping its reference count. PageOffline() pages
with a reference count of 0 can then be skipped when offlining the
pages (like if they were free, however they are not in the buddy).
Anybody who uses PageOffline() pages and does not agree to offline them
(e.g., Hyper-V balloon, XEN balloon, VMWare balloon for 2MB pages) will not
decrement the reference count and make offlining fail when trying to
migrate such an unmovable page. So there should be no observable change.
Same applies to balloon compaction users (movable PageOffline() pages), the
pages will simply be migrated.
Note 1: If offlining fails, a driver has to increment the reference
count again in MEM_CANCEL_OFFLINE.
Note 2: A driver that makes use of this has to be aware that re-onlining
the memory block has to be handled by hooking into onlining code
(online_page_callback_t), resetting the page PageOffline() and
not giving them to the buddy.
Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Anthony Yznaga <anthony.yznaga@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Pingfan Liu <kernelfans@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20200507140139.17083-7-david@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
We also want to unplug online memory (contained in online memory blocks
and, therefore, managed by the buddy), and eventually replug it later.
When requested to unplug memory, we use alloc_contig_range() to allocate
subblocks in online memory blocks (so we are the owner) and send them to
our hypervisor. When requested to plug memory, we can replug such memory
using free_contig_range() after asking our hypervisor.
We also want to mark all allocated pages PG_offline, so nobody will
touch them. To differentiate pages that were never onlined when
onlining the memory block from pages allocated via alloc_contig_range(), we
use PageDirty(). Based on this flag, virtio_mem_fake_online() can either
online the pages for the first time or use free_contig_range().
It is worth noting that there are no guarantees on how much memory can
actually get unplugged again. All device memory might completely be
fragmented with unmovable data, such that no subblock can get unplugged.
We are not touching the ZONE_MOVABLE. If memory is onlined to the
ZONE_MOVABLE, it can only get unplugged after that memory was offlined
manually by user space. In normal operation, virtio-mem memory is
suggested to be onlined to ZONE_NORMAL. In the future, we will try to
make unplug more likely to succeed.
Add a module parameter to control if online memory shall be touched.
As we want to access alloc_contig_range()/free_contig_range() from
kernel module context, export the symbols.
Note: Whenever virtio-mem uses alloc_contig_range(), all affected pages
are on the same node, in the same zone, and contain no holes.
Acked-by: Michal Hocko <mhocko@suse.com> # to export contig range allocator API
Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20200507140139.17083-6-david@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Merge more updates from Andrew Morton:
"More mm/ work, plenty more to come
Subsystems affected by this patch series: slub, memcg, gup, kasan,
pagealloc, hugetlb, vmscan, tools, mempolicy, memblock, hugetlbfs,
thp, mmap, kconfig"
* akpm: (131 commits)
arm64: mm: use ARCH_HAS_DEBUG_WX instead of arch defined
x86: mm: use ARCH_HAS_DEBUG_WX instead of arch defined
riscv: support DEBUG_WX
mm: add DEBUG_WX support
drivers/base/memory.c: cache memory blocks in xarray to accelerate lookup
mm/thp: rename pmd_mknotpresent() as pmd_mkinvalid()
powerpc/mm: drop platform defined pmd_mknotpresent()
mm: thp: don't need to drain lru cache when splitting and mlocking THP
hugetlbfs: get unmapped area below TASK_UNMAPPED_BASE for hugetlbfs
sparc32: register memory occupied by kernel as memblock.memory
include/linux/memblock.h: fix minor typo and unclear comment
mm, mempolicy: fix up gup usage in lookup_node
tools/vm/page_owner_sort.c: filter out unneeded line
mm: swap: memcg: fix memcg stats for huge pages
mm: swap: fix vmstats for huge pages
mm: vmscan: limit the range of LRU type balancing
mm: vmscan: reclaim writepage is IO cost
mm: vmscan: determine anon/file pressure balance at the reclaim root
mm: balance LRU lists based on relative thrashing
mm: only count actual rotations as LRU reclaim cost
...
pmd_present() is expected to test positive after pmdp_mknotpresent() as
the PMD entry still points to a valid huge page in memory.
pmdp_mknotpresent() implies that given PMD entry is just invalidated from
MMU perspective while still holding on to pmd_page() referred valid huge
page thus also clearing pmd_present() test. This creates the following
situation which is counter intuitive.
[pmd_present(pmd_mknotpresent(pmd)) = true]
This renames pmd_mknotpresent() as pmd_mkinvalid() reflecting the helper's
functionality more accurately while changing the above mentioned situation
as follows. This does not create any functional change.
[pmd_present(pmd_mkinvalid(pmd)) = true]
This is not applicable for platforms that define own pmdp_invalidate() via
__HAVE_ARCH_PMDP_INVALIDATE. Suggestion for renaming came during a
previous discussion here.
https://patchwork.kernel.org/patch/11019637/
[anshuman.khandual@arm.com: change pmd_mknotvalid() to pmd_mkinvalid() per Will]
Link: http://lkml.kernel.org/r/1587520326-10099-3-git-send-email-anshuman.khandual@arm.com
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Link: http://lkml.kernel.org/r/1584680057-13753-3-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit 8f182270df ("mm/swap.c: flush lru pvecs on compound page
arrival") THP would not stay in pagevec anymore. So the optimization made
by commit d965432234 ("thp: increase split_huge_page() success rate")
doesn't make sense anymore, which tries to unpin munlocked THPs from
pagevec by draining pagevec.
Draining lru cache before isolating THP in mlock path is also unnecessary.
b676b293fb ("mm, thp: fix mapped pages avoiding unevictable list on
mlock") added it and 9a73f61bdb ("thp, mlock: do not mlock PTE-mapped
file huge pages") accidentally carried it over after the above
optimization went in.
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Link: http://lkml.kernel.org/r/1585946493-7531-1-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ba841078cd ("mm/mempolicy: Allow lookup_node() to handle fatal signal")
has added a special casing for 0 return value because that was a possible
gup return value when interrupted by fatal signal. This has been fixed by
ae46d2aa6a ("mm/gup: Let __get_user_pages_locked() return -EINTR for
fatal signal") in the mean time so ba841078cd can be reverted.
This patch however doesn't go all the way to revert it because the check
for 0 is wrong and confusing here. Firstly it is inherently unsafe to
access the page when get_user_pages_locked returns 0 (aka no page
returned).
Fortunatelly this will not happen because get_user_pages_locked will not
return 0 when nr_pages > 0 unless FOLL_NOWAIT is specified which is not
the case here. Document this potential error code in gup code while we
are at it.
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Xu <peterx@redhat.com>
Link: http://lkml.kernel.org/r/20200421071026.18394-1-mhocko@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The commit 2262185c5b ("mm: per-cgroup memory reclaim stats") added
PGLAZYFREE, PGACTIVATE & PGDEACTIVATE stats for cgroups but missed
couple of places and PGLAZYFREE missed huge page handling. Fix that.
Also for PGLAZYFREE use the irq-unsafe function to update as the irq is
already disabled.
Fixes: 2262185c5b ("mm: per-cgroup memory reclaim stats")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: http://lkml.kernel.org/r/20200527182947.251343-1-shakeelb@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Many of the callbacks called by pagevec_lru_move_fn() does not correctly
update the vmstats for huge pages. Fix that. Also __pagevec_lru_add_fn()
use the irq-unsafe alternative to update the stat as the irqs are
already disabled.
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: http://lkml.kernel.org/r/20200527182916.249910-1-shakeelb@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When LRU cost only shows up on one list, we abruptly stop scanning that
list altogether. That's an extreme reaction: by the time the other list
starts thrashing and the pendulum swings back, we may have no recent age
information on the first list anymore, and we could have significant
latencies until the scanner has caught up.
Soften this change in the feedback system by ensuring that no list
receives less than a third of overall pressure, and only distribute the
other 66% according to LRU cost. This ensures that we maintain a minimum
rate of aging on the entire workingset while it's being pressured, while
still allowing a generous rate of convergence when the relative sizes of
the lists need to adjust.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-15-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The VM tries to balance reclaim pressure between anon and file so as to
reduce the amount of IO incurred due to the memory shortage. It already
counts refaults and swapins, but in addition it should also count
writepage calls during reclaim.
For swap, this is obvious: it's IO that wouldn't have occurred if the
anonymous memory hadn't been under memory pressure. From a relative
balancing point of view this makes sense as well: even if anon is cold and
reclaimable, a cache that isn't thrashing may have equally cold pages that
don't require IO to reclaim.
For file writeback, it's trickier: some of the reclaim writepage IO would
have likely occurred anyway due to dirty expiration. But not all of it -
premature writeback reduces batching and generates additional writes.
Since the flushers are already woken up by the time the VM starts writing
cache pages one by one, let's assume that we'e likely causing writes that
wouldn't have happened without memory pressure. In addition, the per-page
cost of IO would have probably been much cheaper if written in larger
batches from the flusher thread rather than the single-page-writes from
kswapd.
For our purposes - getting the trend right to accelerate convergence on a
stable state that doesn't require paging at all - this is sufficiently
accurate. If we later wanted to optimize for sustained thrashing, we can
still refine the measurements.
Count all writepage calls from kswapd as IO cost toward the LRU that the
page belongs to.
Why do this dynamically? Don't we know in advance that anon pages require
IO to reclaim, and so could build in a static bias?
First, scanning is not the same as reclaiming. If all the anon pages are
referenced, we may not swap for a while just because we're scanning the
anon list. During this time, however, it's important that we age
anonymous memory and the page cache at the same rate so that their
hot-cold gradients are comparable. Everything else being equal, we still
want to reclaim the coldest memory overall.
Second, we keep copies in swap unless the page changes. If there is
swap-backed data that's mostly read (tmpfs file) and has been swapped out
before, we can reclaim it without incurring additional IO.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-14-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We split the LRU lists into anon and file, and we rebalance the scan
pressure between them when one of them begins thrashing: if the file cache
experiences workingset refaults, we increase the pressure on anonymous
pages; if the workload is stalled on swapins, we increase the pressure on
the file cache instead.
With cgroups and their nested LRU lists, we currently don't do this
correctly. While recursive cgroup reclaim establishes a relative LRU
order among the pages of all involved cgroups, LRU pressure balancing is
done on an individual cgroup LRU level. As a result, when one cgroup is
thrashing on the filesystem cache while a sibling may have cold anonymous
pages, pressure doesn't get equalized between them.
This patch moves LRU balancing decision to the root of reclaim - the same
level where the LRU order is established.
It does this by tracking LRU cost recursively, so that every level of the
cgroup tree knows the aggregate LRU cost of all memory within its domain.
When the page scanner calculates the scan balance for any given individual
cgroup's LRU list, it uses the values from the ancestor cgroup that
initiated the reclaim cycle.
If one sibling is then thrashing on the cache, it will tip the pressure
balance inside its ancestors, and the next hierarchical reclaim iteration
will go more after the anon pages in the tree.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-13-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since the LRUs were split into anon and file lists, the VM has been
balancing between page cache and anonymous pages based on per-list ratios
of scanned vs. rotated pages. In most cases that tips page reclaim
towards the list that is easier to reclaim and has the fewest actively
used pages, but there are a few problems with it:
1. Refaults and LRU rotations are weighted the same way, even though
one costs IO and the other costs a bit of CPU.
2. The less we scan an LRU list based on already observed rotations,
the more we increase the sampling interval for new references, and
rotations become even more likely on that list. This can enter a
death spiral in which we stop looking at one list completely until
the other one is all but annihilated by page reclaim.
Since commit a528910e12 ("mm: thrash detection-based file cache sizing")
we have refault detection for the page cache. Along with swapin events,
they are good indicators of when the file or anon list, respectively, is
too small for its workingset and needs to grow.
For example, if the page cache is thrashing, the cache pages need more
time in memory, while there may be colder pages on the anonymous list.
Likewise, if swapped pages are faulting back in, it indicates that we
reclaim anonymous pages too aggressively and should back off.
Replace LRU rotations with refaults and swapins as the basis for relative
reclaim cost of the two LRUs. This will have the VM target list balances
that incur the least amount of IO on aggregate.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-12-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When shrinking the active file list we rotate referenced pages only when
they're in an executable mapping. The others get deactivated. When it
comes to balancing scan pressure, though, we count all referenced pages as
rotated, even the deactivated ones. Yet they do not carry the same cost
to the system: the deactivated page *might* refault later on, but the
deactivation is tangible progress toward freeing pages; rotations on the
other hand cost time and effort without getting any closer to freeing
memory.
Don't treat both events as equal. The following patch will hook up LRU
balancing to cache and anon refaults, which are a much more concrete cost
signal for reclaiming one list over the other. Thus, remove the maybe-IO
cost bias from page references, and only note the CPU cost for actual
rotations that prevent the pages from getting reclaimed.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-11-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Operations like MADV_FREE, FADV_DONTNEED etc. currently move any affected
active pages to the inactive list to accelerate their reclaim (good) but
also steer page reclaim toward that LRU type, or away from the other
(bad).
The reason why this is undesirable is that such operations are not part of
the regular page aging cycle, and rather a fluke that doesn't say much
about the remaining pages on that list; they might all be in heavy use,
and once the chunk of easy victims has been purged, the VM continues to
apply elevated pressure on those remaining hot pages. The other LRU,
meanwhile, might have easily reclaimable pages, and there was never a need
to steer away from it in the first place.
As the previous patch outlined, we should focus on recording actually
observed cost to steer the balance rather than speculating about the
potential value of one LRU list over the other. In that spirit, leave
explicitely deactivated pages to the LRU algorithm to pick up, and let
rotations decide which list is the easiest to reclaim.
[cai@lca.pw: fix set-but-not-used warning]
Link: http://lkml.kernel.org/r/20200522133335.GA624@Qians-MacBook-Air.local
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Qian Cai <cai@lca.pw>
Link: http://lkml.kernel.org/r/20200520232525.798933-10-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, scan pressure between the anon and file LRU lists is balanced
based on a mixture of reclaim efficiency and a somewhat vague notion of
"value" of having certain pages in memory over others. That concept of
value is problematic, because it has caused us to count any event that
remotely makes one LRU list more or less preferrable for reclaim, even
when these events are not directly comparable and impose very different
costs on the system. One example is referenced file pages that we still
deactivate and referenced anonymous pages that we actually rotate back to
the head of the list.
There is also conceptual overlap with the LRU algorithm itself. By
rotating recently used pages instead of reclaiming them, the algorithm
already biases the applied scan pressure based on page value. Thus, when
rebalancing scan pressure due to rotations, we should think of reclaim
cost, and leave assessing the page value to the LRU algorithm.
Lastly, considering both value-increasing as well as value-decreasing
events can sometimes cause the same type of event to be counted twice,
i.e. how rotating a page increases the LRU value, while reclaiming it
succesfully decreases the value. In itself this will balance out fine,
but it quietly skews the impact of events that are only recorded once.
The abstract metric of "value", the murky relationship with the LRU
algorithm, and accounting both negative and positive events make the
current pressure balancing model hard to reason about and modify.
This patch switches to a balancing model of accounting the concrete,
actually observed cost of reclaiming one LRU over another. For now, that
cost includes pages that are scanned but rotated back to the list head.
Subsequent patches will add consideration for IO caused by refaulting of
recently evicted pages.
Replace struct zone_reclaim_stat with two cost counters in the lruvec, and
make everything that affects cost go through a new lru_note_cost()
function.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-9-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When we calculate the relative scan pressure between the anon and file LRU
lists, we have to assume that reclaim_stat can contain zeroes. To avoid
div0 crashes, we add 1 to all denominators like so:
anon_prio = swappiness;
file_prio = 200 - anon_prio;
[...]
/*
* The amount of pressure on anon vs file pages is inversely
* proportional to the fraction of recently scanned pages on
* each list that were recently referenced and in active use.
*/
ap = anon_prio * (reclaim_stat->recent_scanned[0] + 1);
ap /= reclaim_stat->recent_rotated[0] + 1;
fp = file_prio * (reclaim_stat->recent_scanned[1] + 1);
fp /= reclaim_stat->recent_rotated[1] + 1;
spin_unlock_irq(&pgdat->lru_lock);
fraction[0] = ap;
fraction[1] = fp;
denominator = ap + fp + 1;
While reclaim_stat can contain 0, it's not actually possible for ap + fp
to be 0. One of anon_prio or file_prio could be zero, but they must still
add up to 200. And the reclaim_stat fraction, due to the +1 in there, is
always at least 1. So if one of the two numerators is 0, the other one
can't be. ap + fp is always at least 1. Drop the + 1.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-8-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When the splitlru patches divided page cache and swap-backed pages into
separate LRU lists, the pressure balance between the lists was biased to
account for the fact that streaming IO can cause memory pressure with a
flood of pages that are used only once. New page cache additions would
tip the balance toward the file LRU, and repeat access would neutralize
that bias again. This ensured that page reclaim would always go for
used-once cache first.
Since e986850598 ("mm,vmscan: only evict file pages when we have
plenty"), page reclaim generally skips over swap-backed memory entirely as
long as there is used-once cache present, and will apply the LRU balancing
when only repeatedly accessed cache pages are left - at which point the
previous use-once bias will have been neutralized. This makes the
use-once cache balancing bias unnecessary.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-7-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We activate cache refaults with reuse distances in pages smaller than the
size of the total cache. This allows new pages with competitive access
frequencies to establish themselves, as well as challenge and potentially
displace pages on the active list that have gone cold.
However, that assumes that active cache can only replace other active
cache in a competition for the hottest memory. This is not a great
default assumption. The page cache might be thrashing while there are
enough completely cold and unused anonymous pages sitting around that we'd
only have to write to swap once to stop all IO from the cache.
Activate cache refaults when their reuse distance in pages is smaller than
the total userspace workingset, including anonymous pages.
Reclaim can still decide how to balance pressure among the two LRUs
depending on the IO situation. Rotational drives will prefer avoiding
random IO from swap and go harder after cache. But fundamentally, hot
cache should be able to compete with anon pages for a place in RAM.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-6-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
They're the same function, and for the purpose of all callers they are
equivalent to lru_cache_add().
[akpm@linux-foundation.org: fix it for local_lock changes]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-5-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With the advent of fast random IO devices (SSDs, PMEM) and in-memory swap
devices such as zswap, it's possible for swap to be much faster than
filesystems, and for swapping to be preferable over thrashing filesystem
caches.
Allow setting swappiness - which defines the rough relative IO cost of
cache misses between page cache and swap-backed pages - to reflect such
situations by making the swap-preferred range configurable.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-4-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Having statistics on pages scanned and pages reclaimed for both anon and
file pages makes it easier to evaluate changes to LRU balancing.
While at it, clean up the stat-keeping mess for isolation, putback,
reclaim stats etc. a bit: first the physical LRU operation (isolation and
putback), followed by vmstats, reclaim_stats, and then vm events.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-3-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The reclaim code that balances between swapping and cache reclaim tries to
predict likely reuse based on in-memory reference patterns alone. This
works in many cases, but when it fails it cannot detect when the cache is
thrashing pathologically, or when we're in the middle of a swap storm.
The high seek cost of rotational drives under which the algorithm evolved
also meant that mistakes could quickly result in lockups from too
aggressive swapping (which is predominantly random IO). As a result, the
balancing code has been tuned over time to a point where it mostly goes
for page cache and defers swapping until the VM is under significant
memory pressure.
The resulting strategy doesn't make optimal caching decisions - where
optimal is the least amount of IO required to execute the workload.
The proliferation of fast random IO devices such as SSDs, in-memory
compression such as zswap, and persistent memory technologies on the
horizon, has made this undesirable behavior very noticable: Even in the
presence of large amounts of cold anonymous memory and a capable swap
device, the VM refuses to even seriously scan these pages, and can leave
the page cache thrashing needlessly.
This series sets out to address this. Since commit ("a528910e12ec mm:
thrash detection-based file cache sizing") we have exact tracking of
refault IO - the ultimate cost of reclaiming the wrong pages. This allows
us to use an IO cost based balancing model that is more aggressive about
scanning anonymous memory when the cache is thrashing, while being able to
avoid unnecessary swap storms.
These patches base the LRU balance on the rate of refaults on each list,
times the relative IO cost between swap device and filesystem
(swappiness), in order to optimize reclaim for least IO cost incurred.
History
I floated these changes in 2016. At the time they were incomplete and
full of workarounds due to a lack of infrastructure in the reclaim code:
We didn't have PageWorkingset, we didn't have hierarchical cgroup
statistics, and problems with the cgroup swap controller. As swapping
wasn't too high a priority then, the patches stalled out. With all
dependencies in place now, here we are again with much cleaner,
feature-complete patches.
I kept the acks for patches that stayed materially the same :-)
Below is a series of test results that demonstrate certain problematic
behavior of the current code, as well as showcase the new code's more
predictable and appropriate balancing decisions.
Test #1: No convergence
This test shows an edge case where the VM currently doesn't converge at
all on a new file workingset with a stale anon/tmpfs set.
The test sets up a cold anon set the size of 3/4 RAM, then tries to
establish a new file set half the size of RAM (flat access pattern).
The vanilla kernel refuses to even scan anon pages and never converges.
The file set is perpetually served from the filesystem.
The first test kernel is with the series up to the workingset patch
applied. This allows thrashing page cache to challenge the anonymous
workingset. The VM then scans the lists based on the current
scanned/rotated balancing algorithm. It converges on a stable state where
all cold anon pages are pushed out and the fileset is served entirely from
cache:
noconverge/5.7-rc5-mm noconverge/5.7-rc5-mm-workingset
Scanned 417719308.00 ( +0.00%) 64091155.00 ( -84.66%)
Reclaimed 417711094.00 ( +0.00%) 61640308.00 ( -85.24%)
Reclaim efficiency % 100.00 ( +0.00%) 96.18 ( -3.78%)
Scanned file 417719308.00 ( +0.00%) 59211118.00 ( -85.83%)
Scanned anon 0.00 ( +0.00%) 4880037.00 ( )
Swapouts 0.00 ( +0.00%) 2439957.00 ( )
Swapins 0.00 ( +0.00%) 257.00 ( )
Refaults 415246605.00 ( +0.00%) 59183722.00 ( -85.75%)
Restore refaults 0.00 ( +0.00%) 54988252.00 ( )
The second test kernel is with the full patch series applied, which
replaces the scanned/rotated ratios with refault/swapin rate-based
balancing. It evicts the cold anon pages more aggressively in the
presence of a thrashing cache and the absence of swapins, and so converges
with about 60% of the IO and reclaim activity:
noconverge/5.7-rc5-mm-workingset noconverge/5.7-rc5-mm-lrubalance
Scanned 64091155.00 ( +0.00%) 37579741.00 ( -41.37%)
Reclaimed 61640308.00 ( +0.00%) 35129293.00 ( -43.01%)
Reclaim efficiency % 96.18 ( +0.00%) 93.48 ( -2.78%)
Scanned file 59211118.00 ( +0.00%) 32708385.00 ( -44.76%)
Scanned anon 4880037.00 ( +0.00%) 4871356.00 ( -0.18%)
Swapouts 2439957.00 ( +0.00%) 2435565.00 ( -0.18%)
Swapins 257.00 ( +0.00%) 262.00 ( +1.94%)
Refaults 59183722.00 ( +0.00%) 32675667.00 ( -44.79%)
Restore refaults 54988252.00 ( +0.00%) 28480430.00 ( -48.21%)
We're triggering this case in host sideloading scenarios: When a host's
primary workload is not saturating the machine (primary load is usually
driven by user activity), we can optimistically sideload a batch job; if
user activity picks up and the primary workload needs the whole host
during this time, we freeze the sideload and rely on it getting pushed to
swap. Frequently that swapping doesn't happen and the completely inactive
sideload simply stays resident while the expanding primary worklad is
struggling to gain ground.
Test #2: Kernel build
This test is a a kernel build that is slightly memory-restricted (make -j4
inside a 400M cgroup).
Despite the very aggressive swapping of cold anon pages in test #1, this
test shows that the new kernel carefully balances swap against cache
refaults when both the file and the cache set are pressured.
It shows the patched kernel to be slightly better at finding the coldest
memory from the combined anon and file set to evict under pressure. The
result is lower aggregate reclaim and paging activity:
z 5.7-rc5-mm 5.7-rc5-mm-lrubalance
Real time 210.60 ( +0.00%) 210.97 ( +0.18%)
User time 745.42 ( +0.00%) 746.48 ( +0.14%)
System time 69.78 ( +0.00%) 69.79 ( +0.02%)
Scanned file 354682.00 ( +0.00%) 293661.00 ( -17.20%)
Scanned anon 465381.00 ( +0.00%) 378144.00 ( -18.75%)
Swapouts 185920.00 ( +0.00%) 147801.00 ( -20.50%)
Swapins 34583.00 ( +0.00%) 32491.00 ( -6.05%)
Refaults 212664.00 ( +0.00%) 172409.00 ( -18.93%)
Restore refaults 48861.00 ( +0.00%) 80091.00 ( +63.91%)
Total paging IO 433167.00 ( +0.00%) 352701.00 ( -18.58%)
Test #3: Overload
This next test is not about performance, but rather about the
predictability of the algorithm. The current balancing behavior doesn't
always lead to comprehensible results, which makes performance analysis
and parameter tuning (swappiness e.g.) very difficult.
The test shows the balancing behavior under equivalent anon and file
input. Anon and file sets are created of equal size (3/4 RAM), have the
same access patterns (a hot-cold gradient), and synchronized access rates.
Swappiness is raised from the default of 60 to 100 to indicate equal IO
cost between swap and cache.
With the vanilla balancing code, anon scans make up around 9% of the total
pages scanned, or a ~1:10 ratio. This is a surprisingly skewed ratio, and
it's an outcome that is hard to explain given the input parameters to the
VM.
The new balancing model targets a 1:2 balance: All else being equal,
reclaiming a file page costs one page IO - the refault; reclaiming an anon
page costs two IOs - the swapout and the swapin. In the test we observe a
~1:3 balance.
The scanned and paging IO numbers indicate that the anon LRU algorithm we
have in place right now does a slightly worse job at picking the coldest
pages compared to the file algorithm. There is ongoing work to improve
this, like Joonsoo's anon workingset patches; however, it's difficult to
compare the two aging strategies when the balancing between them is
behaving unintuitively.
The slightly less efficient anon reclaim results in a deviation from the
optimal 1:2 scan ratio we would like to see here - however, 1:3 is much
closer to what we'd want to see in this test than the vanilla kernel's
aging of 10+ cache pages for every anonymous one:
overload-100/5.7-rc5-mm-workingset overload-100/5.7-rc5-mm-lrubalance-realfile
Scanned 533633725.00 ( +0.00%) 595687785.00 ( +11.63%)
Reclaimed 494325440.00 ( +0.00%) 518154380.00 ( +4.82%)
Reclaim efficiency % 92.63 ( +0.00%) 86.98 ( -6.03%)
Scanned file 484532894.00 ( +0.00%) 456937722.00 ( -5.70%)
Scanned anon 49100831.00 ( +0.00%) 138750063.00 ( +182.58%)
Swapouts 8096423.00 ( +0.00%) 48982142.00 ( +504.98%)
Swapins 10027384.00 ( +0.00%) 62325044.00 ( +521.55%)
Refaults 479819973.00 ( +0.00%) 451309483.00 ( -5.94%)
Restore refaults 426422087.00 ( +0.00%) 399914067.00 ( -6.22%)
Total paging IO 497943780.00 ( +0.00%) 562616669.00 ( +12.99%)
Test #4: Parallel IO
It's important to note that these patches only affect the situation where
the kernel has to reclaim workingset memory, which is usually a
transitionary period. The vast majority of page reclaim occuring in a
system is from trimming the ever-expanding page cache.
These patches don't affect cache trimming behavior. We never swap as long
as we only have use-once cache moving through the file LRU, we only
consider swapping when the cache is actively thrashing.
The following test demonstrates this. It has an anon workingset that
takes up half of RAM and then writes a file that is twice the size of RAM
out to disk.
As the cache is funneled through the inactive file list, no anon pages are
scanned (aside from apparently some background noise of 10 pages):
5.7-rc5-mm 5.7-rc5-mm-lrubalance
Scanned 10714722.00 ( +0.00%) 10723445.00 ( +0.08%)
Reclaimed 10703596.00 ( +0.00%) 10712166.00 ( +0.08%)
Reclaim efficiency % 99.90 ( +0.00%) 99.89 ( -0.00%)
Scanned file 10714722.00 ( +0.00%) 10723435.00 ( +0.08%)
Scanned anon 0.00 ( +0.00%) 10.00 ( )
Swapouts 0.00 ( +0.00%) 7.00 ( )
Swapins 0.00 ( +0.00%) 0.00 ( +0.00%)
Refaults 92.00 ( +0.00%) 41.00 ( -54.84%)
Restore refaults 0.00 ( +0.00%) 0.00 ( +0.00%)
Total paging IO 92.00 ( +0.00%) 48.00 ( -47.31%)
This patch (of 14):
Currently, THP are counted as single pages until they are split right
before being swapped out. However, at that point the VM is already in the
middle of reclaim, and adjusting the LRU balance then is useless.
Always account THP by the number of basepages, and remove the fixup from
the splitting path.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-1-hannes@cmpxchg.org
Link: http://lkml.kernel.org/r/20200520232525.798933-2-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The previous patches have simplified the access rules around
page->mem_cgroup somewhat:
1. We never change page->mem_cgroup while the page is isolated by
somebody else. This was by far the biggest exception to our rules and
it didn't stop at lock_page() or lock_page_memcg().
2. We charge pages before they get put into page tables now, so the
somewhat fishy rule about "can be in page table as long as it's still
locked" is now gone and boiled down to having an exclusive reference to
the page.
Document the new rules. Any of the following will stabilize the
page->mem_cgroup association:
- the page lock
- LRU isolation
- lock_page_memcg()
- exclusive access to the page
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Reviewed-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Link: http://lkml.kernel.org/r/20200508183105.225460-20-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Swapin faults were the last event to charge pages after they had already
been put on the LRU list. Now that we charge directly on swapin, the
lrucare portion of the charge code is unused.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Link: http://lkml.kernel.org/r/20200508183105.225460-19-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Right now, users that are otherwise memory controlled can easily escape
their containment and allocate significant amounts of memory that they're
not being charged for. That's because swap readahead pages are not being
charged until somebody actually faults them into their page table. This
can be exploited with MADV_WILLNEED, which triggers arbitrary readahead
allocations without charging the pages.
There are additional problems with the delayed charging of swap pages:
1. To implement refault/workingset detection for anonymous pages, we
need to have a target LRU available at swapin time, but the LRU is not
determinable until the page has been charged.
2. To implement per-cgroup LRU locking, we need page->mem_cgroup to be
stable when the page is isolated from the LRU; otherwise, the locks
change under us. But swapcache gets charged after it's already on the
LRU, and even if we cannot isolate it ourselves (since charging is not
exactly optional).
The previous patch ensured we always maintain cgroup ownership records for
swap pages. This patch moves the swapcache charging point from the fault
handler to swapin time to fix all of the above problems.
v2: simplify swapin error checking (Joonsoo)
[hughd@google.com: fix livelock in __read_swap_cache_async()]
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2005212246080.8458@eggly.anvils
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Link: http://lkml.kernel.org/r/20200508183105.225460-17-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Without swap page tracking, users that are otherwise memory controlled can
easily escape their containment and allocate significant amounts of memory
that they're not being charged for. That's because swap does readahead,
but without the cgroup records of who owned the page at swapout, readahead
pages don't get charged until somebody actually faults them into their
page table and we can identify an owner task. This can be maliciously
exploited with MADV_WILLNEED, which triggers arbitrary readahead
allocations without charging the pages.
Make swap swap page tracking an integral part of memcg and remove the
Kconfig options. In the first place, it was only made configurable to
allow users to save some memory. But the overhead of tracking cgroup
ownership per swap page is minimal - 2 byte per page, or 512k per 1G of
swap, or 0.04%. Saving that at the expense of broken containment
semantics is not something we should present as a coequal option.
The swapaccount=0 boot option will continue to exist, and it will
eliminate the page_counter overhead and hide the swap control files, but
it won't disable swap slot ownership tracking.
This patch makes sure we always have the cgroup records at swapin time;
the next patch will fix the actual bug by charging readahead swap pages at
swapin time rather than at fault time.
v2: fix double swap charge bug in cgroup1/cgroup2 code gating
[hannes@cmpxchg.org: fix crash with cgroup_disable=memory]
Link: http://lkml.kernel.org/r/20200521215855.GB815153@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Link: http://lkml.kernel.org/r/20200508183105.225460-16-hannes@cmpxchg.org
Debugged-by: Hugh Dickins <hughd@google.com>
Debugged-by: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A few cleanups to streamline the swap controller setup:
- Replace the do_swap_account flag with cgroup_memory_noswap. This
brings it in line with other functionality that is usually available
unless explicitly opted out of - nosocket, nokmem.
- Remove the really_do_swap_account flag that stores the boot option
and is later used to switch the do_swap_account. It's not clear why
this indirection is/was necessary. Use do_swap_account directly.
- Minor coding style polishing
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Link: http://lkml.kernel.org/r/20200508183105.225460-15-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are no more users. RIP in peace.
[arnd@arndb.de: fix an unused-function warning]
Link: http://lkml.kernel.org/r/20200528095640.151454-1-arnd@arndb.de
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Link: http://lkml.kernel.org/r/20200508183105.225460-14-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With the page->mapping requirement gone from memcg, we can charge anon and
file-thp pages in one single step, right after they're allocated.
This removes two out of three API calls - especially the tricky commit
step that needed to happen at just the right time between when the page is
"set up" and when it's "published" - somewhat vague and fluid concepts
that varied by page type. All we need is a freshly allocated page and a
memcg context to charge.
v2: prevent double charges on pre-allocated hugepages in khugepaged
[hannes@cmpxchg.org: Fix crash - *hpage could be ERR_PTR instead of NULL]
Link: http://lkml.kernel.org/r/20200512215813.GA487759@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Link: http://lkml.kernel.org/r/20200508183105.225460-13-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With rmap memcg locking already in place for NR_ANON_MAPPED, it's just a
small step to remove the MEMCG_RSS_HUGE wart and switch memcg to the
native NR_ANON_THPS accounting sites.
[hannes@cmpxchg.org: fixes]
Link: http://lkml.kernel.org/r/20200512121750.GA397968@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reviewed-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org> [build-tested]
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Link: http://lkml.kernel.org/r/20200508183105.225460-12-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Memcg maintains a private MEMCG_RSS counter. This divergence from the
generic VM accounting means unnecessary code overhead, and creates a
dependency for memcg that page->mapping is set up at the time of charging,
so that page types can be told apart.
Convert the generic accounting sites to mod_lruvec_page_state and friends
to maintain the per-cgroup vmstat counter of NR_ANON_MAPPED. We use
lock_page_memcg() to stabilize page->mem_cgroup during rmap changes, the
same way we do for NR_FILE_MAPPED.
With the previous patch removing MEMCG_CACHE and the private NR_SHMEM
counter, this patch finally eliminates the need to have page->mapping set
up at charge time. However, we need to have page->mem_cgroup set up by
the time rmap runs and does the accounting, so switch the commit and the
rmap callbacks around.
v2: fix temporary accounting bug by switching rmap<->commit (Joonsoo)
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Link: http://lkml.kernel.org/r/20200508183105.225460-11-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Memcg maintains private MEMCG_CACHE and NR_SHMEM counters. This
divergence from the generic VM accounting means unnecessary code overhead,
and creates a dependency for memcg that page->mapping is set up at the
time of charging, so that page types can be told apart.
Convert the generic accounting sites to mod_lruvec_page_state and friends
to maintain the per-cgroup vmstat counters of NR_FILE_PAGES and NR_SHMEM.
The page is already locked in these places, so page->mem_cgroup is stable;
we only need minimal tweaks of two mem_cgroup_migrate() calls to ensure
it's set up in time.
Then replace MEMCG_CACHE with NR_FILE_PAGES and delete the private
NR_SHMEM accounting sites.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Link: http://lkml.kernel.org/r/20200508183105.225460-10-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Anonymous compound pages can be mapped by ptes, which means that if we
want to track NR_MAPPED_ANON, NR_ANON_THPS on a per-cgroup basis, we have
to be prepared to see tail pages in our accounting functions.
Make mod_lruvec_page_state() and lock_page_memcg() deal with tail pages
correctly, namely by redirecting to the head page which has the
page->mem_cgroup set up.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Link: http://lkml.kernel.org/r/20200508183105.225460-9-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When memcg uses the generic vmstat counters, it doesn't need to do
anything at charging and uncharging time. It does, however, need to
migrate counts when pages move to a different cgroup in move_account.
Prepare the move_account function for the arrival of NR_FILE_PAGES,
NR_ANON_MAPPED, NR_ANON_THPS etc. by having a branch for files and a
branch for anon, which can then divided into sub-branches.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Reviewed-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Link: http://lkml.kernel.org/r/20200508183105.225460-8-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The uncharge batching code adds up the anon, file, kmem counts to
determine the total number of pages to uncharge and references to drop.
But the next patches will remove the anon and file counters.
Maintain an aggregate nr_pages in the uncharge_gather struct.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Reviewed-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Link: http://lkml.kernel.org/r/20200508183105.225460-7-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The try/commit/cancel protocol that memcg uses dates back to when pages
used to be uncharged upon removal from the page cache, and thus couldn't
be committed before the insertion had succeeded. Nowadays, pages are
uncharged when they are physically freed; it doesn't matter whether the
insertion was successful or not. For the page cache, the transaction
dance has become unnecessary.
Introduce a mem_cgroup_charge() function that simply charges a newly
allocated page to a cgroup and sets up page->mem_cgroup in one single
step. If the insertion fails, the caller doesn't have to do anything but
free/put the page.
Then switch the page cache over to this new API.
Subsequent patches will also convert anon pages, but it needs a bit more
prep work. Right now, memcg depends on page->mapping being already set up
at the time of charging, so that it can maintain its own MEMCG_CACHE and
MEMCG_RSS counters. For anon, page->mapping is set under the same pte
lock under which the page is publishd, so a single charge point that can
block doesn't work there just yet.
The following prep patches will replace the private memcg counters with
the generic vmstat counters, thus removing the page->mapping dependency,
then complete the transition to the new single-point charge API and delete
the old transactional scheme.
v2: leave shmem swapcache when charging fails to avoid double IO (Joonsoo)
v3: rebase on preceeding shmem simplification patch
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Link: http://lkml.kernel.org/r/20200508183105.225460-6-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The cgroup swaprate throttling is about matching new anon allocations to
the rate of available IO when that is being throttled. It's the io
controller hooking into the VM, rather than a memory controller thing.
Rename mem_cgroup_throttle_swaprate() to cgroup_throttle_swaprate(), and
drop the @memcg argument which is only used to check whether the preceding
page charge has succeeded and the fault is proceeding.
We could decouple the call from mem_cgroup_try_charge() here as well, but
that would cause unnecessary churn: the following patches convert all
callsites to a new charge API and we'll decouple as we go along.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Reviewed-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Link: http://lkml.kernel.org/r/20200508183105.225460-5-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 215c02bc33 ("tmpfs: fix shmem_getpage_gfp() VM_BUG_ON")
recognized that hole punching can race with swapin and removed the
BUG_ON() for a truncated entry from the swapin path.
The patch also added a swapcache deletion to optimize this rare case:
Since swapin has the page locked, and free_swap_and_cache() merely
trylocks, this situation can leave the page stranded in swapcache.
Usually, page reclaim picks up stale swapcache pages, and the race can
happen at any other time when the page is locked. (The same happens for
non-shmem swapin racing with page table zapping.) The thinking here was:
we already observed the race and we have the page locked, we may as well
do the cleanup instead of waiting for reclaim.
However, this optimization complicates the next patch which moves the
cgroup charging code around. As this is just a minor speedup for a race
condition that is so rare that it required a fuzzer to trigger the
original BUG_ON(), it's no longer worth the complications.
Suggested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Link: http://lkml.kernel.org/r/20200511181056.GA339505@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
